Pre-release and unused content
Before a game gets released one might see enemies and places that aren't in the released game, because they are taken out for unknown reasons. The elements that were once in the game but were taken out are called Beta Elements.
Beta Elements
Here is a list of Beta Elements appearing in Mario games:
Super Mario Bros. 2
The game was originally to have a SNROM-02 chip rather than the final versions TSROM-04. This means that it had CHR-RAM instead of CHR-ROM and could utilize batteries. This was probably changed because the original chip had 1 MB rather than the final version's 2 MB. The story originally had more orange characters, background and text, a yellow frame a light yellow "painting" and a red logo. Originally, it was ellipses between "Extra Life" and the number of lives, something that was restored in Super Mario All-Stars. The characters didn't change much, however, Princess Peach, Mario and Luigi didn't have sclera in the original version. Also, the "shrinking" Peach missed two pixels on either side, and Toad did have two pixels fewer on the right down-corner. All their sprites for holding things also changed. The player couldn't run by holding down the B button. The beta also had normal pictures for each character, through this maybe not was available at the time. The original lamp was originally to be in the game, instead of the potion.
For even more information, see The Mushroom Kingdom: Lost Bytes: Prototypes: Super Mario Bros. 2 and Doki Doki Panic.
Super Mario Bros. 3
There were going to be two new enemies called Gold Cheep Cheep (a golden version of a Cheep-Cheep), and Green Parabeetles (green colored Parabeetles). The Gold Cheep Cheeps would come in groups and swim faster than regular Cheep-Cheeps and the Green Parabeetle is a green Parabeetle that flies faster than normal ones. The game coding reveals an item-sized Toad icon among some of the game's suits; this is interpreted by several as a sort of "Toad Suit", although it makes no changes to gameplay when granted to Mario. This is likely due to it being scrapped early and never given any purpose. Designers also considered a power-up to turn Mario into a Centaur (half-man, half-horse), although this was rejected (Tilden 1990, 21).
Koopa Troopas and and Hammer Bros. were going to host the mini-games. They were replaced by Toad. However, it could also be possible that they were all around at the same time, but all got scrapped except for one due to memory size. There were also different kinds of mini-games, similar to the ones in New Super Mario Bros..
Finally, fifteen extra levels exist within the coding of Super Mario Bros. 3. Some of these are strange and unique, while others bear much resemblance to levels in the final version and were very likely redone as those. Also, the back of the box of some copies of Super Mario Bros. 3 depicts Mario traversing a hilly grassland stage with tons of Parabeetles and two Note Blocks about. This particular stage is not any of the lost ones present on the cartridge, nor is it in the final game. It could even be a press mock-up from Nintendo. The "special" boxes also feature a beta map of Grass Land.
- Koop.gif
A Koopa Troopa hosting an item mini-game in Super Mario Bros. 3. - Hammer.gif
A Hammer Bro. hosting a card mini-game in Super Mario Bros. 3. - Toad.gif
Super Mario Bros. 3's "Toad Suit" as it appears in the game's programming.
Super Mario World
Dinosaur Land was drastically different, possessing an appearance similar to the various kingdoms of Super Mario Bros. 3. Specifically, it was to feature things such as Toad Houses (which could possibly mean that Toads were once considered to populate Dinosaur Land) and more Super Mario Bros. 3-style Fortresses.
SNES test cartridges also exist and, among other things (some of which are Mario-related), they include an early build of Super Mario World. These cartridges reveal that, at one point, Goombas were to be able to be stomped (even earlier test cartridges show that Goombas also once possessed their normal, mushroom-like appearance rather than the Goom-like Goombas seen in the final game and later builds), Koopa Troopas were to walk on all fours, and normal Piranha Plants and even Venus Fire Traps were to have been present. These elements were used in the Super Mario World cartoon. Interestingly, several of these cartridges' beta sprites were merely simple Super Mario Bros. 3 edits. Lastly, the Super Leaf and Raccoon Mario form were both present in early builds.
Further exploration of the game cartridge showed that a Lakitu and an unknown blue bird were going to appear on the Overworld map. They were also several unused sprites and levels. Source There was also a dull, less-colourful title screen.
Early screenshots of the Game Boy Advance port (Super Mario World: Super Mario Advance 2) showed that the HUD wasn't even changed, unlike the final version. [1]
A beta screenshot of Dinosaur Land from Super Mario World. 
Another screenshot of the beta-version of Dinosaur Land.
Super Mario World 2: Yoshi's Island
This game was going to have more forms Yoshi could turn into: a Mushroom, a Tree, and a Plane (most likely replaced by the helicopter form). There are Tweeter sprites present in the game's coding that looked identical to the Tweeters of Super Mario All-Stars, and a Super Mario All-Stars Shy Guy is also present within the game. There are also some Bob-Ombs using the wrong palette. It is possible that the programmers were merely using these sprites as references for enemy sprites that they were remaking, and either didn't use the Tweeter or it was never meant to be used and taken from Super Mario All-Stars by mistake. There is also a frowning, rock-like block present in the game's coding, and, perhaps even more oddly, a hulking, barrel-throwing, tie-clad Grinder that seems to deliberately resemble Donkey Kong. It is possible that this gorilla-like Grinder would be a Kamek-strengthened Grinder boss and clever reference to Mario's first enemy.
The "Yoshi Plane", a canceled transformation from Super Mario World 2: Yoshi's Island. 
The "Yoshi Mushroom", another canceled transformation from Super Mario World 2: Yoshi's Island. 
The "Yoshi Tree"", another canceled transformation from Super Mario World 2: Yoshi's Island.
Super Mario Land 2
Early screenshots showed of the English version showed that there was a different, less detailed tittle screen. [2]
DK Jungle Climber
In several screenshots, there are some beta levels such as a foggy area that was possibly the beta Panic Factory, also there's another screenshot which shows an underwater level in the sea with a Lockjaw. There were originally swing-like objects that were in the game. Also some objects and backgrounds had different pallettes.
- Betajungleclimber.JPG
The strange unused swings. - BetaJungleClimber2.jpg
A Beta Jungle Beach - BetaJungleClimber3.jpg
A foggy Panic Factory - DKJB4.jpg
A group of different paletted pegs - DKJC5.jpg
An unused backround
Donkey Kong 64
Beta-screenshots of Donkey Kong 64 showed that Donkey Kong's Treehouse originally had a shower stall in it with a poster of Banjo and Kazooie on it. Also, the boss Mad Jack was originally known as "Junk-in-the-Box" and was also drastically different in appearance. Mad Jack/Junk-in-the-Box was also originally a mini-boss fought in the R&D Room in Frantic Factory instead of being a full boss fought at the area's end.
Also, the weapons the Kongs wielded in the early screenshots looked like real-world weapons instead of the wooded, somewhat cartoonish ones seen in the final version of the game. Donkey Kong's Coconut Shooter resembled a double-barreled shotgun while Diddy Kong's Peanut Popguns resembled actual pistols. This was most likely changed for the E-rating.
Another factor is that Army Dillo originally was able to hover in the air and shoot fire in the air in Jungle Japes, which he was able to do in Crystal Caves in the final version of the game.
The shower stall and Banjo and Kazooie poster originally found in Donkey Kong's Treehouse in Donkey Kong 64. 
Junk-in-the-Box, what Mad Jack looked like before Donkey Kong 64 was fully completed.
Donkey Kong Country
In an old Scribes page on the Rareware website there was mention of there once being a Giraffe Animal Buddy planned to appear in Donkey Kong Country; this Giraffe character was dropped for unknown reasons, though one of his mentioned abilities was that he would allow Donkey Kong to crawl up his neck and reach high items and secrets.
It is debated whether or not the plans for this Giraffe buddy were actually real though, as Rare could have simply been making a joke at the expense of fan who had made a rather odd request for a Giraffe to appear in an upcoming Donkey Kong game.
Donkey Kong Country 2: Diddy's Kong Quest
On the Rare Witch Project website once had previews of several upcoming enemies and characters for Donkey Kong Country 2: Diddy's Kong Quest. Among these enemies was a sinister looking character (or perhaps generic enemy) simply dubbed "Mr. X". Mr. X was a white (or perhaps skeletal) Kremling wearing a large black jacket covered in army medals, he also possessed two small hooks for hands.
- Mr. X.jpg
Mr. X, an abandoned character from Donkey Kong Country 2: Diddy's Kong Quest.
Donkey Kong Land
Several creatures and characters who were originally going in this game were abandoned for unknown reasons. These creatures and characters included a fish enemy named Pucka, an unnamed Kong who wore a hat and a what appears to be a baby ram named Ram Bunkshus. All these unused characters were first advertised in an old issue of Nintendo Power magazine, which included pictures of them.
Pucka, the unused fish enemy from Donkey Kong Land. 
Ram Bunkshus, a possible Animal Buddy dropped from the final version of Donkey Kong Land. 
The unnamed, hatted Kong dropped from the final version of Donkey Kong Land.
Donkey Kong Land 2
Donkey Kong Land 2 originally had the sub-title "Diddy's Kong Quest", this was later removed, probably because it would cause people to think the game was an exact port of the game it was based on, Donkey Kong Country 2: Diddy's Kong Quest.
Game & Watch Gallery 4
A few pre-release screenshot showed that the characters had different sprites. The "Game Select" screen was completely different. The Game Data also contains a few more unused sprites. [3]
Donkey Kong Land 3
Donkey Kong Land 3 originally had the sub-title "The Race Against Time", it was later removed, presumably due to the fact that the other two installments in the Donkey Kong Land series did not possess, so it would seem slightly pointless to give Donkey Kong Land 3 one.
Luigi's Mansion
Luigi's Poltergust 3000 was originally supposed to have a heat meter. If Luigi kept his vacuum on for too long, it would burst into flames, causing Luigi to lose HP. There also originally was a pink ghost that would scream behind Luigi causing him to lose 50 HP. The orange ghosts originally were blue, and had a big nose. The pink prototype ghosts closely resembled the final version orange ghosts albeit pink.
There was also supposed to be more interactivity, such as Luigi sliding down a stairway, and a lamp breaking. Originally, the Boo Radar was supposed to show you where ghosts were, but not Boos. Originally the mansion also had an RPG type of quality which included real-time changes of rooms and also an underground dungeon-like basement.
There also was a lost graphic. In the first picture below shows the beta parlor. In the room, it had an extra side-table in front of the china cabinet.
- Luigibusters42 640w.jpg
A prototype screen shot with the heat meter and a different Game Boy Horror. Note: the beta side-table. - Luigiscream.jpg
A lost graphic. - Pinkghost.jpg
The pink prototype ghost.
Mario's Tennis
The character list in this game's coding features the name "CASSARIN", which is notable for, unlike the other characters, not having any sprites. "Cassarin" happens to be Japanese for "Catherine", which is Birdo's Japanese name; it can therefore be assumed that Birdo was initially planned for playability in Mario's Tennis.
Mario & Luigi: Partners in Time
A certain beta screenshot depicts Mario, Luigi, and their baby selves fighting two red shoe-clad Blooper foes in the Vim Factory. Almost nothing is known about this Blooper creature, which was unused, although the timing of the taking of the screen shot featuring them (which depicts Luigi, upon being thrust by a Trampoline, stomping one) conveniently shows fans both its normal and pained poses. Another early screen shot shows the gang using a Mix Flower on two Boo Guys in Hollijolli Village, while Boo Guys were not present in this area in the final game. Finally, it may be notable that Baby Mario's initial artwork erroneously depicted him as having red shoes rather than his normal blue ones (this mistake was eventually changed and the artwork was re-released), although his shoe coloration would appear to have always been consistent throughout all of the actual game's programming.
The bizarre shoe-wearing Bloopers from Mario & Luigi: Partners in Time. 
Boo Guys in Hollijolli Village, where they were never seen in the final version of Mario & Luigi: Partners in Time. - MnL2 BetaLogo.jpg
The beta game logo.
Mario & Luigi: Superstar Saga
Wario, Fox McCloud, Captain Olimar, Samus Aran, Link, and even an Excitebike Racer were going to show up in the Starbeans Café after Mario and Luigi made coffee, instead of E. Gadd (who was only scheduled to make one appearance). The Bean Fruits were also going to be multi-colored, and a few unused items include Neon Beans, a Game and Watch, and something known as the "Spiritual Bros.", which may be a badge. One of this game's more interesting Beta Elements is that the name "Sharkbone" appears alongside names for enemies found in Gwarhar Lagoon in the game's coding, and "Sharkbone" is presumed to be an alternate name for the ???? enemies that are actually found in the final game (these enemies actually can come in a bony shark form, although they are also found in a living, Cheep-Cheep-like variety). Even more interestingly, a Nintendo Power guide actually referred to the ????s' undead shark forms as "Sharkbones" and their living Cheep-Cheep forms as "Puffer-Cheeps", which were actually completely different Cheep-Cheep varieties present in the final game; it is presumed that Nintendo based this naming off of beta material (and it may be worth noting that the German version of Mario and Luigi: Superstar Saga replaces "Sharkbone" with "Sand-Cheep").
Mario Kart 64
A Magikoopa was going to be in this game playable, but got replaced by Donkey Kong. Also note that the Character select screen was going to have the racer face towards the player. The working title was Mario Kart R. In certain gameplay screenshots, the Feather Item, which it appeared in Super Mario Kart, was going to be included in the list of items of the game.
- Mario Kart 64 Beta 01.gif
The beta title screen of Mario Kart 64. It was named Super Mario Kart R at this point. 
A Magikoopa would have once been playable in Mario Kart 64.And Bowser looks slightly different.
Mario Kart: Double Dash!!
The models of the characters are from Super Smash Bros Melee, and Mario and Luigi are seen in this game's only known beta trailer driving separately and each having a simple, blue kart. It was originally called Mario Kart for Gamecube, and it is likely that this early build of Mario Kart: Double Dash!! was completely scrapped and redone for the final game, as it looks nothing like it. However, when one of the final versions was made, the textures, speedometer and HUD, and pictures looked different.
The original title for Mario Kart: Double Dash. 
Mario and Luigi in a beta Mario Kart: Double Dash. - BetaMarioKartDoubleDash5thplace.jpg
Mario Kart Double Dash in later version with different pictures and textures.
Mario Kart DS
This game's Retro Grand Prix was going to include a few more tracks, such as Mario Circuit from Mario Kart: Double Dash!!(Dismantled for the new Mario Circuit.), Koopa Troopa Beach (under the name "Nokonoko Course") from Mario Kart 64, and Mario Kart: Double Dash!!'s Block City battle area. There was also an mysterious "Dokan Course" stage with no textures and Moo Moo Farm music [1], as well as a simple, circular test area smaller than even Baby Park; both of these (and the latter one for sure) could've been debugging stages not planned for inclusion in the final game. These areas can still be accessed using Action Replay DS. Waluigi Pinball was also slightly different (mostly in texture and music, the latter of which was strangely from Yoshi Falls) in betas, albeit probably a programming error.[2] Demo copies of the game actually showed it with quite a few object differences (such as more bumpers and a less direct launch towards the beginning). The demo version also depicted DK Pass with (perhaps more thematic for its eponymous character) a grassland theme rather than a snow one, with a lone Thwomp near the finish line, as well as many other small differences mostly regarding walls and jumps. Finally, demo version guides released for stores by Nintendo depicted the Chain Chomp (which could not actually be retrieved in the demo version itself) as an item; it is presumed that this Chomp munition would work in a manner similar to that of the Chain Chomps in Mario Kart: Double Dash!!, making it likely that Chain Chomps were removed from the game in favor of Bullet Bills (although the listing of the Chain Chomp in these beta guides may have been a simple mistake, though this is unlikely).
- MKDS BetaImage.jpg
The screenshot contains a different status bar of the rank rows. There is also a speedometer very similar to the one from MK:DD, which is absent from MKDS. Additionally, the lap is originally placed at the bottom of the dual screen, the item panel is in the middle, and the 2nd place logo is gold. - Ss mkds pre32.jpg
A more beachier Cheep Cheep Beach.
Mario Kart Super Circuit
Early Nintendo Power screenshots showed that the character had different, "Super-Deformed" sprites. Said screenshots also showed that the HUD was different. Some tracks also had more detailed background. [4]
Mario Party DS
Wiggler's Garden was originally called Petey's Greenhouse, with Petey Piranha needing help as a member of Petey's army(aka Piranha Plant) had betrayed him and was destroying his greenhouse. Also Toadsworth was going to appear in the item house, but was replaced by a Monty Mole. He still is not absent, as he is mentioned in the item gallery a few times, just never seen.
Another thing is that the players used to have their own boxes at the top screen that have the "X" in the Coins storage and the Stars storage. In the final version, it was removed possibly because Coins can reach over two hundred. It was also going to have Wi-Fi, but scrapped possibly due to memory constraints, lack of time, or because other Mario Party games didn't have Wi-Fi.
The beta version of the player's box. Note the "x" marks in both of the Coins and Stars storage.
Mario Power Tennis
In the intro of the game where Wario and Waluigi are drawing on the scorechart in the left the player can see Toad and Toadette's heads. It is unknown if they were going to be playable and they forgot to take their faces off the score chart.
Mario vs. Donkey Kong 2: March of the Minis
The top screen looked different. It was always outside on the top screen. Also, Cool Kongs used to wear spiked helmets, had purple goggles, and were darker, along with the "C" on their ties being a "W." The sprite used for when a Mini-Mario hanged onto a Cool Kong's tie was also different, with the Mini-Mario facing forward as he did so. Hearts were also present (apparently as collectible items) for unknown reasons. Mini-Shy Guys were dark red instead of the red-pink color used in the final game. Wall Jump bars were also originally red, being reddish-pink (much like Mini-Shy Guys) in the final game. Falling poses were the same has unactivated poses as well. Additionally, Gold Mini-Marios were going to appear in every level, by looking at the top screen of screenshots.
- MvsDK2 Betaimage1.jpg
A beta version of the top screen.
New Super Mario Bros.
The working title for this game was Super Mario Bros. DS. Also, during early stages of production, Mega Goombas were going to be a generic species (the result of a Goomba colliding with a Super Mushroom and powering up) rather than an individual boss. (It is possible that other enemies were to be compatible with this situation, too, considering the giant enemies like Super Dry Bones and Super Piranha Plant that remain in the game in generic, already-large forms.) There was also supposed to be a Mario and Luigi co-op mode at a time. Interestingly, an illustration of beta map icons still exists as a screenshot on page twelve of the final game's manual. There were originally three item reserve spots rather than one. There also was an underwater stage which also featured Manta Ray in VS. Mode. Spindrift was also supposed to be in the game, but got replaced by the blue spinning platforms in World 1-3 and other levels.
In another image, it's possible to obtain the Blue Shell by first defeating a Blue Koopa Troopa. Then when the player Ground Pounds on the shell, the player gets in the shell and becomes Shell Mario. This feature is removed possibly because the designers wanted a power-up that can be obtained from a ? Block, however it survives in Vs. Mode. Mega Mushrooms were also originally intended to be red. The advertisement accenting the Vs. mode revealed some levels that were not available on the final release, including a desert stage, an underwater stage and a few others. The Mega Mushroom was going to look like a large Super Mushroom rather than a chubby-looking mushroom that was yellow with red spots.
It was possible to kick and punch in the game but is also removed.
And in the beta version the player can hold three items, just like can apreciate in the status screen, but in the original only can hold one item.
- Whomp Attack.jpg
A Giant Whomp attacking Mario and Luigi. Also note the blue box from Super Mario 64. - The Original NSMB.jpg
The original opening title of New Super Mario Bros. - Rope Land.jpg
Some type of rope land. 
The Mega Goomba species. - Giant Manta.jpg
An unused underwater stage. - Double Trouble.jpg
Notice the designs of the item boxes and Spindrift. 
Mario and Luigi going around the level. Additionally, the bottom screen looks different. 
A demonstration of how to obtain the Blue Shell powerup. 
The original World 4 castle.
An unused world.
Paper Mario
Early screenshots of this game showed that Poochy was going to play some sort of role in the game. Another screenshot showed that Nep-Enuts were going to be in this game also. Also the early version of Forever Forest showed that it would be much smaller, with all the forest's trees having sinister faces. Paper Mario was also originally going to be named Super Mario RPG 2, though due to complications involving Square Enix, the makers of Super Mario RPG: Legend of the Seven Stars, the name was changed to Super Mario Adventure and later Paper Mario. Also, it was originally in development for the failed Nintendo 64DD. However, it was released in cartridge. A screenshot had also shown a strange, beta Whale.
The release version of the game contains some scrapped Badges that can be accessed with a gameshark or similar. A fully functional Dark Paratroopa enemy exists in the ROM, as well. Finally, Goombaria's name and icon are both present in the game's list of partners for Mario.
Ther's an image that has the text MARIO RPG in the floor, the blocks give mushrooms, if you talk to the goomba, or to the Star Road, the game freezes. There's a hammer in the chest. Going trought the door with a "0" leads you to a real part in the game, you die with one attack, and after dying you get to Shy Guy's Tox Box.
Here is seen a POW Block, which isn't shown in the real game, if you hit it, it will just shake.
There's a part where if you go through any of the doors, you will reappear in the same place.
A Beta Element, shows a place where you have a clone, also there's an useless switch and Goompa, who says nothing.
In a strange part, unshown in the game, there are koopas who will transform into your partners. Ther's also a strange wave of unknown use.
- SMRPG2 BetaScreenshot1.jpg
Paper Mario's title screen from when it was called Super Mario RPG 2. - PaperPoochy.jpg
A beta-screenshot of Paper Mario with Poochy in it. - PaperNep-Enut.jpg
A Nep-Enut as seen in a beta-screenshot of Paper Mario. - Papermariobetaforeverforest.jpg
A beta screenshot of the Forever Forest with trees in Paper Mario. - Smrpg2.jpg
An early screen shot of Paper Mario. - Paper Mario Beta Partners.GIF
Unused partners remain in the game's code. - Papermariobeta001.jpg
Strange screenshot of Paper Maio with some strange elements. - Papermariousnap0.jpg
An useless POW Block. - Papermariousnap0006yb3.jpg
Tough it's exitless, there is Star Piece hidden. - Papermariousnap0004cs3.jpg
The useless switch, your clone, and Goompa. - Papermariousnap0008tt7.jpg
A strange wave on the floor and a line of koopas. 
The koopas transformed.
Paper Mario: The Thousand-Year Door
This game was initially going to simply be called Paper Mario 2 and feature a far different logo, one reminiscent of the original Paper Mario's logo. There were also many unused badges. See Badges for information on them.
All of the partners from Paper Mario were going to appear but were cut-off as well. Bow and Parakarry were the only ones left. There was also a strange robot creature and two palette swaps of Screamy. Bobbery also had a prototype sprite, which depicts him wearing army gear. There was also going to be a probable mini-boss called Dark Atomic Boo. Dark Atomic Boo would be a Dark Boo version of Atomic Boo, and some have theorized that it may have been a more powerful Atomic Boo fought in the Dark Boo-inhabited Poshley Sanctum.
Also, in the original trailer, one can see a HP Plus badge that is located on a ledge beyond a moving platform which has a wall over it in mid course (and assumedly could be reached with the help of Vivian). None of this made it into the final game (except the area where these things are, minus the things themselves of course). The trailer also showed that Item Shops would be labeled with Mushrooms rather than the Fire Flowers seen in the final game. Red Bones was initially named "Red Koopa Skeleton". In the same trailer you can see that "Tornado Jump" was initially called "Hurricane Jump".
Aside from scenery, there are also two songs that were unused in the game. One sounds like a theme used for an introduction of a character, and the other sounds like a boss fight. This may mean that another character was going to be in the game but was written out of the final version like these songs.
First song: Unknown Theme
- It should be noted that this song is somewhat similar to the introduction of a new Pixl in Super Paper Mario.
Second song: Beta Boss Theme
Strangely, the officially site depicts KP Pete as a red Koopa Troopa and a trash-talker. This may be a Beta Element.
- TTYDbetascreenshot.png
The beta location of the HP Plus Badge. - Gauge.gif
The bizarre, unused robot from Paper Mario: The Thousand-Year Door. - Better old bobbery.PNG
A prototype sprite of Bobbery. - Hamburger.gif
An unused Spinia creature. - Dark Boo.PNG
Dark Atomic Boo glares. - Dark Atomic Boo.PNG
Dark Atomic Boo's "confused" pose. - Goombario1000yeardoor.gif
Goombario's unused sprite from Paper Mario: The Thousand-Year Door. - Kooper1000yeardoor.gif
Kooper's unused sprite from Paper Mario: The Thousand-Year Door. - Bombette1000yeardoor.gif
Bombette's unused sprite from Paper Mario: The Thousand-Year Door. - Watt1000yeardoor.gif
Watt's unused sprite from Paper Mario: The Thousand-Year Door. - Sushi1000yeardoor.gif
Sushie's unused sprite from Paper Mario: The Thousand-Year Door. - Lakilester1000yeardoor.gif
Lakilester's unused sprite from Paper Mario: The Thousand-Year Door. - Moa.gif
A creature who is the same species as Screamy from the game but didn't appear. - Darkmoa.gif
A dark version of Screamy's species. 
The game's beta logo before the final version of the game.
Super Mario 64
This game was originally to be called Super Mario FX, using the FX Chip and was also being planned for the Super Nintendo. Luigi has also been said to been playable in the FX, but was scrapped for unknown reasons. In the Beta version, it would've had a numbered health bar instead of the pointed one. Many stages and bars would be different. Thwomp would also have a scarier look and Mario would have a different jump (one that let him spin around after a triple jump in a way similar to the result of being hit by a Tweester in Shifting Sand Land). Early screenshots also show a tan Cheep-Cheep, not found in the final game. Mario was voiced differently (possessing a screechy, childlike voice rather than his current Italian accent), Bowser sounded more tiger-like. There was also going to be a Blargg that would appear in the Lethal Lava Land stage.
Other beta elements include a Yoshi egg making it possible that Yoshi was going to be playable or ridable, the Bowser's Castle, textures with lava outside the castle instead of water, two text-circles (like the one in the Super Mario Bros. series), a leaf (Possibly a Super Leaf), strange stars and moons symbols, loads of unused wall and floor textures, a strange unused palm tree, an scary looking door with a bat alá Bowser, and a beta tree.
- SM64beta.jpg
Beta screenshot of Super Mario 64. 
A beta Blargg in an old version of Super Mario 64.
Super Mario 64 DS
The working title for this game was Super Mario 64x4. Also, several beta screenshots were released for the game. Originally, all four characters could fight Bowser at the same time, and fly. This feature was removed, as the four characters can only fight Bowser by their own (with Yoshi utilizing hats to be able to swing Bowser). Also at E3 2004, there was a demo called Mario's Face, where the user could use the stylus to mess around with Mario or Wario's face, and have them be 3D or outlined like a cartoon. This could have possibly been the beta Mario Mini for Super Mario 64 DS. The caps the player uses were originally enclosed in boxes labeled M, L, and W. The boxes can still be found in the test level. [3] Also, early screenshots depicted Wario with his original long shirt sleeves before adopting the shorter ones for the final product. The game was also originally was supposed to have a co-op mode but was canned probably due to memory constraints.
Unused Box art for Super Mario 64 DS. - Flying.JPG
All four characters flying in an early promotional screenshot. (Note that this technically could be possible in the multiplayer where anyone can fly.) - All4.PNG
All four fighting Bowser under the castle. 
Like the last image. Additionally, the status bar is at the bottom of the dual screen before the final version. The status bar also looks different. 
The hud isn't supposed to pop up right now. 
The four characters are running.
Super Mario Advance
In addition to Super Mario Bros. 2, a remade version of Super Mario Bros. was also meant to be available, but was cut.Template:Fact
Super Mario Galaxy
Beta images of Super Mario Galaxy showed conjecturally named species called Cosmic Toads, a kind of Toad that lives in outer space. They were supposed to live in Toad Houses in various galaxies. They told Mario how to use Launch Stars or would give him Star Bits. Rabbits were also going to be able to change into Cosmic Toads. The Starshade Brothers from Superstar Saga looked similar to them. Their role was likely replaced by Lumas.
Also, there was going to be a level called "Star World," not to be confused with the Super Mario World "Star World." "Honeyhive Galaxy" was originally called "Honeybee Galaxy," and "Rosalina" was originally "Rosetta" (A direct transliteration of her Japanese name.) Also, according to one of the IGN.com screenshots, Bowser was originally going to be fought on an arena on a magma planet instead of a glassy planet like in the first 2 battles. Also in Toy Time Galaxy, the player can use a Train Set hidden in the platforms when the player looks just to the right, hidden there probably because it's easier than just getting rid of it.
In the beta, the player had to hold B and point at the Star Bits to grab them. this was later changed because they settled on using the B button to fire Star Bits. Also, in the beta version, Mario could kick Star Bits around.
The first planet in the Good Egg Galaxy looks different of both sides in the beta version than the alpha version. Also, in early versions of the game, the Life Meter was more like one in Super Mario 64, having a total of eight HP, and changing color more like the Super Mario 64 version. There was an even earlier version still, which was blue instead of green.
Super Mario 64 voices were used as Mario's voice in early betas as a placeholder. Disappearing green platforms originally did not have a square border around them. There was also supposed to be a galaxy called the "Gale Galaxy" which was probably the prototype for Gusty Garden Galaxy. There also was a prototype sound for grabbing Star Bits.
Another large beta elements, where Asteroid-like Planetoids that would have been all over the game, and taken the place of a huge amount of more unique planets. However, in the final version, they where scrapped for more unique planets. They where most likely simply place holders for planets that had not been created yet.
There was also going to be a giant green Pokey in the Dusty Dune Galaxy. It probably was replaced by Red Pokeys, and it resembled a Poison Pokey. Mario would also be able to lock onto boulders with the Star Cursor and stun them. Electrogoombas would float in the air, doing nothing, and would appear in the Melty Molten Galaxy, which had features and planets from the Dreadnought Galaxy, such as a giant saucer with a floating cube above it, and Topmen. Topmaniac also looked different, and would be fought in the Melty Molten Galaxy. Most of the galaxies would be fused together, and would all have the space background, like the Good Egg Galaxy, the Space Junk Galaxy, and the Gusty Garden Galaxy.
Another strange element is that the original Star Cursor was yellow in color in betas. An even bigger element is that the Star Bit Counter originally said 0/100 in early betas, 000 in the later beta versions, and 0 in the final version. Guppy was also originally going to be a dolphin. He was changed to make him unfriendly. Swoopin' Poinks were originally colored purple. Mario also had an ability to spin to attract coins to him, which he lost in the final version.
In early versions of the game it was also possible to do Star Spins directly after you did an other. In the final version, the player first have to wait before doing an new star spin.
- SMG betalife.PNG
The beta Life Meter - Star World Beta.JPG
"Star World", never to be seen in the final version. (Note the Cosmic Toads) - Beta Ver.jpg
An almost-finished Space Junk Galaxy. - Asteroidplanet.jpg
An asteroid. - Poisonpokeysmg.jpg
A green Pokey. - Beta Topmaniac.PNG
The beta Topmaniac. - Beta GustyGardenPlanet.PNG
The second planet in the Gusty Garden Galaxy's second mission, though different looking. Also note the space background. - 34966484-4d3c-4780-bb60-9e06ae67a83e.JPG
The Beta Version Bit Star meter. - SpaceRabbits.jpg
An early Good Egg Galaxy. Note the appearance of Rabbits. - Beta-comparison.JPG
This area originally had Star Bits on the flowers instead of coins. - Beta-comparison2.JPG
Here is the area from the final game. - 042.jpg
Mario kicking a Goomba.
Super Mario RPG: Legend of the Seven Stars
Looking into the coding of Super Mario RPG: Legend of the Seven Stars reveals several unused enemies (most of which seem to be unused sub-species), including a notorious one known as the Drill Bit. In fact, Drill Bit appears in the game, but does not fight in any battle like a normal enemy. Harlequins were jester-like enemies that never made it into the final game. There is another unused enemy called a Baba Yaga, it looks like a blue colored Fautso. There is an unused (and unnamed) enemy, tentatively called Boshumutt, that resembles a purple Bahamutt with sunglasses and is probably named after Boshi. Source A creature similar to a red Spiny called Super Spike was originally going to appear.White versions Carroboscis were discovered in the games coding. An unused enemy named Lumbler was a blue version of Stumpet and Lumbler has a move set (which points to it probably being taken out later in production). If it made it into the game, it is known that it would have the moves Crystal and an egg shooting attack it shares with Birdo.
Material from an early Nintendo Power shows that the Chancellor was once designed differently, being a more elderly-looking, gray-spotted Toad with a beard. It also showed that at least one Buzzer would be in Mushroom Way, and that Frogfucius's island at Tadpole Pond would be closer and therefore accessed differently. A fishin' variety of Lakitu would be a helper in Booster's Tower, which possessed Magikoopa door guards. (It is notable that no fightable Magikoopas other than the red one thought to be Kamek would appear in the final game.) Mario would also encounter Bowser at an unknown time in Bowser's Keep, and would be pitted against two Shy Aways during this scene. Other material shows that Booster's Tower would also feature Boos, Dry Bones, and less organized pictures.Nimbus Castle would have a longer walkway and more plants.
A beta version of Super Mario RPG was also seen at a 1995 V-Jump Festival, which also focused on the game's programming and therefore showed off several features and various other things not meant to be accessible by normal players even by the game's release. The presentation of this beta showed that Nimbus Land (which was seen in entirety, even including the Nintendo Power beta Nimbus Castle, at the presentation's opening) would have differently styled doorways, being simple open holes labeled with a word seeming to be "HOLLOW" or "HOLLOH" rather than the curtains seen in the final version. The V-Jump presentation also featured an animation of a normal, blue-colored Magikoopa attacking and showed Mario running through Mushroom Way (or perhaps Bandit's Way, as a K-9 was visible) and being chased by several Buzzers, indicating that they would indeed be found en masse in that area in the beta Super Mario RPG: Legend of the Seven Stars. The presentation also briefly showed a beta Yo'ster Isle, which was much larger and oddly seemed to feature no racetrack. The beta version seen in the presentation also gave Moleville a cloud-filled foreground and removed the blue static seen in the Factory's foreground. The majority of Nimbus Castle's interior seen in this beta would appear to simply be more green than that of the final version, although the room where Dodo cleaned Valentina's statues was depicted as different shades of pink (or perhaps red with pink walls), looking nothing like it did in the final version. This room was also completely flipped horizontally for the final version. Melody Bay's composition area also seemed to be longer, and Mario's Pad was depicted as much larger, and Mario's house itself even changed in appearance–– Much like it was in the final version of Super Mario RPG's intro, the V-Jump beta depicted Mario's in-game house as being labeled "Pipe House". A Treasure Box was also seen in the beta Mario's Pad; upon being hit by Mario, this box produced a green, 1-Up Mushroom-like mushroom that in itself was not present in the final game. A pair of Terrapins were also seen guarding an exit from Mario's Pad in this beta. Lastly, the beta even featured three unused battlegrounds, one of which was a dark, musty castle similar in appearance to Belome Temple, A underwater Battle Stage (which appeared to be from in the Sea Area), the other being a star-labeled circle that may have been a simple testing area.Source
Two unused cutscenes regarding a distressed Princess Peach on the balcony of Booster's Tower were left in the game's coding, but did not make the final cut. Interestingly, both were very similar to (but longer than) scenes in the final game. Source
Finally, Luigi was believed to be in, as he appeared in a screenshot.
- Unused Enemies2.PNG
All the Unused enemies. 
A bearded Chancellor in the Super Mario RPG beta. 
A Buzzer in Mushroom Way. 
Mario, Frogfucius, and several Tadpoles at a beta Tadpole Pond. 
A chaotic scene in a beta Booster's Tower. 
A Fishin' Lakitu helps Mario through Booster's Tower. 
A beta version of King and Queen Nimbus' castle in Nimbus Land. 
Bowser directs a pair of Shy Away guardians at his castle. - Underwater.PNG
A underwater Battle Stage not played in the course of the game, but is in the game data. - Rpg fiest.gif
Luigi's appearance.
Super Mario Strikers
Beta videos and beta screenshots showed that there would be no items in the game. Also in the beta version, Donkey Kong wouldn't hit the ball with his feet but with his fists. The costumes were very different as well and Donkey Kong would have another voice. Mario's voice would also be different, making it possible that all characters as well had different voices.
Note in this picture Donkey Kong's bowtie, and The Palace stadium without audience.
Super Mario Sunshine
In Super Mario Sunshine, Delfino Plaza is the main plaza of the game. However, in movies before release, it showed that there was going to be a different plaza (or possible prototype for Delfino Plaza), with a giant Strollin' Stu-like creature walking all over the place, similar to the odd banana-like creature in the test level, and many more different things. It was allegedly called a Tramplin' Stu. The beta also reveals that Humans were intended to be citizens of the plaza. FLUDD was going to be skinnier and Gooper Blooper was going to be dark blue and fought on top of the bridges of Ricco Harbor instead of in the market and helicopter area. Additionally, Mario's health bar would simply be a sun with a number in the middle indicating his health. The water meter was originally placed in the center of the "sun" life meter. The F.L.U.D.D. pack was actually Nintendo's 3rd favorite choice, with many other forms of water-pump functionality suggested. One other notable device in the top 2 was a water gun but was abandoned deciding that some players may render it too violent. There were some abandoned sprites as well, including Yoshi vomiting any water he may have swallowed.
There was also going to be a brown Pokey, and they were going to have white flowers. Source
A test level is playable through an Action Replay. There the player can see Rock Blocks that were edited out, possibly in favor of Watermelons. Also, a small book can be found in an alcove of a cave in the bottom of the bottle in Noki Bay's third episode. Source.
- Gooperbeta.JPG
Gooper Blooper's prototype, Mario's health bar, as well as FLUDD, also looks different than in the final version of Super Mario Sunshine. - Tramplin' Stu.jpg
A giant Strollin' Stu-like creature, cut out of Super Mario Sunshine. Also note that there's another, different beta health bar. - Old FLUDD.jpg
FLUDD's old, thinner design. - Beta.jpg
An unused human citizen of Isle Delfino. - Old Plaza.jpg
An unused plaza on Isle Delfino. - Super mario sunshine 003.jpeg
Sirena Beach's beta Warp Pipe entrance - Ss ms pre07.jpeg
The Brown, unused Pokey. Note the white flowers. - Ss sms pre135.jpg
Mario and a green Yoshi on a bridge at Pianta Village. 
Mario stands with Boos in the background, but their models are completely different. - Mariosunshine betapic.jpg
Mario and a green Yoshi stomp on a Strollin' Stu that is never there in the final version, and the water meter has FLUDD's icon.
Super Paper Mario
This game was originally intended as a Nintendo GameCube game. While on the GameCube, it would appear that all characters' special abilities would be activated with the R-Button rather than the different buttons they had on the final Wii version.[5] Most Pixls (initially "Fairens") would be activated with the X-Button,[6] and all Pixls but Tippi seemed to be one Pixl who would morph into others to use "Fairy Abilities" (such as Fairy Toss, Thoreau's predecessor, and Fairy Hammer, Cudge's predecessor).[7] It is unknown what button would activate Tippi in the GameCube version.
The game was eventually moved to Wii exclusive (as it is now), although it at times was (as aforementioned) considered to be only for GameCube and even for both consoles, a la The Legend of Zelda: Twilight Princess.[8] By summer of 2007, Super Paper Mario was moved to Wii.[9]
An early version of the game had a different looking version of the Whoa Zone from Chapter 4, and Mario is still wearing a helmet, when he wasn't supposed to be. Also, an early screenshot shows Mario under the effects of the Mega Star, but is colored very differently (giving his current colors rather than the initial ones seen in Super Mario Bros.). Oddly, he is shown in his proper colors in the official trailer that was released at the same time, which may imply that the screenshot's release way simply delayed.
In a screenshot featuring Big Blooper, there's an odd Pixl that is shaped like a ladder. It never actually appears in the final game. This could be an early version of Carrie. Also, in the same screenshot, Tippi is present, but she was kidnapped by Francis at this point in the game, and by the time she is rescued, also Big Blooper cannot be fought again. Finally, the scene depicting Bowser and Peach's wedding at the beginning of the game was also slightly different in beta versions; the ceremony would appear to have once taken place in more of a room than an open area, there were no flowers decorating the columns, the rising of the Chaos Heart was surprisingly light, and Count Bleck raised his cloak up earlier than he did in the final version. Plus, in the screenshot, Peach is standing instead of having been knocked over, and Bowser looks normal than shocked.
- Betawhoazone.PNG
An early Whoa Zone in Super Paper Mario. - Betaspmmegamario.jpg
Mega Mario has different colors here. - Betapixl.PNG
The mysterious "ladder Pixl". - Wedding.jpg
Bowser and Peach's beta wedding.
Super Princess Peach
The Koopalings were originally going to be in the game, but were taken out for unknown reasons. All of the Koopalings' lost sprites have been discovered by now. Oddly enough, Morton's sprites were spread around the internet long before those of his siblings. Also, Roy was given a green shell instead of a pink shell. This may have been either a design change or a mistake. Lost sprites of Glad and Calm Goombas have also recently been discovered. In the game, only Mad and Sad variants appeared. The Glad Goomba (which was a bronze or yellow color), based on its sprite, could be able to bounce or dance around (as the glossary says most Glad Enemies do), and the Calm one (which was green and rather sickly-looking), based on the Calm Enemies, it would probably be sleeping and act like a normal Goomba when Peach is too fast. Finally, a very early screenshot shows the "Peach's face" screen, which ended up on the bottom screen, to be on the top screen and totally devoid of Heart Panels and also having a bright green, solid background and a different design for Peach. The fact that the Heart Panels, which were used to change Vibes in the final game, are lacking from this screenshot suggests that Super Princess Peach was once planned to not use Vibes and be a more average side-scroller.
The unused Koopaling sprites from Super Princess Peach. - Sppgladcalmgoombas.PNG
The unused Glad/Calm Goomba sprites from Super Princess Peach. - SPPbeta.jpg
The Heart Panel-less screenshot of Super Princess Peach, which happens to take place in Fury Volcano.
Super Smash Bros.
Two beta Kirby stages are only playable with a GameShark. The stages have strange elements, such as invisible barriers. A working Dream Land stage can be viewed in the "How to Play" tutorial, which itself can be seen by waiting on the title screen. Also, in the character select, the question mark boxes were supposed to be colored and Safron City also had pink with purple on the rooftops.
- Ss ssb 1.jpg
An early character select.
Super Smash Bros. Melee
Through an Action Replay, a large, gray stage with the background appearing to be some kind of pub, is accessible. The music is the same as used on Fox and Falco's stage Corneria. This is assumed to be a test stage because of its name, which on the debug menu is TEST. There are also four stages, named AKANEIA (a possible predecessor to Castle Siege from Super Smash Bros. Brawl, a homeworld for Fire Emblem), 10-2, IceTop (a possible precursor to the Summit stage from the sequel, which belongs to the Ice Climbers), and Dummy, a test stage that freezes the game when opened. In addition to this, the entire Debug Menu, which was used in pre-release testing, can be used when the game is hacked, allowing for complete editing of anything in the game. Giga Bowser, both male and female Fighting Wire Frames, Master Hand, Crazy Hand, and even Sandbag are all playable (to a limited extent) via the Debug Menu.
Early screenshots showed the Motion-Sensor Bomb to be much different; these screenshots actually showed it to be a Proximity Mine from Perfect Dark rather than the Motion-Sensor Bomb from "TOP SECRET" (actually GoldenEye 007) that appeared in the final game. A screenshot of this Proximity Mine's trophy has also been released, and this screenshot shows that (in an almost cheap manner) the text in the Proximity Mine trophy was only tampered minorly (with only a few removals of references to Perfect Dark) for the final Motion-Sensor Bomb trophy. Why the Perfect Dark Proximity Mine was changed to a GoldenEye 007 Motion-Sensor Bomb remains unknown to this day and is rather ridiculous, especially considering that the games from which the items originated were even made by the same company, although the fact that Nintendo hides the Motion-Sensor Bomb's trophy's debuting game entry with the words "TOP SECRET" in the final game suggest that the item change may very well have had to do with copyright infringement. The "Temple" stage originally had an elevator that led to the bottom of the stage, and had a fixed appearance. Players could also could walk through the laboratory in Great Bay. Stages Yoshi's Story and Kingdom I had different designs altogether. Onett's music also sounded different.
Super Smash Bros. Melee's beta Motion-Sensor Bomb's trophy. This happens to be what the Sensor Bomb looks like in the Japanese version of the game, but reasons on the change on the North American version are unknown. 
The old character-selection screen before the final version of the game. Note that Kirby, Peach, Zelda, and Ice Climbers are missing. 
The same select screen at E3 2001. 
Zelda missing in this picture from the Japan website 
The test level.
Super Smash Bros. Brawl
Some of the game world icons were initially the same as in the previous two games, but they were revised as time went on (Mario's Mushroom icon was refined and given spots, the Poké Ball icon has the top half colored in to properly represent how it is usually red, etc.). Also, the description for the My Music options originally said, "Adjust how often a song will appear on this stage." It has since been revised in a general tone to say, "Adjust how often songs appear on stages." Solid Snake was also meant to be more muscular, and was to have a gray suit rather than blue. The original Snake was less modernized and his down smash was going to be a more realistic bomb. Wario Bike, Drill Rush, Trophy Base, Summit, Halberd, Rainbow Cruise, and "The Flowers That Bloom on the Note" were originally called Wario Chopper, Triple Dash, Trophy Stand, The Summit, Battle Ship Halberd, Rainbow Ride, and, "Flowers Bloom in the Echoes" respectively. It's unknown why they changed these names, however, they likely changed Rainbow Ride because it was a Melee stage, in which it was misnamed Rainbow Cruise. Lastly, there were scenes taking place before the events of the Subspace Emissary where the Subspace Army takes over the Halberd and King Dedede unintentionally stalls Meta Knight from preventing it from happening. Masahiro Sakurai confirmed that he decided to cut this out and an update was made to confirm this together with how various events and characters in the Subspace Emissary comes together.
Also, unused files for Dixie Kong, Toon Zelda, Toon Sheik, and "Pra_Mai" (speculated to be Plusle & Minun of Pokemon fame) were found as scrapped newcomers. There were also files for Dr. Mario, Mewtwo, and Roy, possibly meaning that they were planned to be brought back at one time, or that their data was imported for some reason. A scrapped Assist Trophy for Ridley was also found. It was most likely scrapped in favor of a Boss version of Ridley. The full list of files can be seen here: Source Donkey Kong and Diddy Kong had a early trophy before they had the one in the game. Source
A less gloomy version of The Battlefield Fortress. 
The beta icons. - SnakeBomb.png
The beta down smash mine.
Yoshi's Island DS
As stated below, Yoshi's Island DS (which was initially referred to as Yoshi's Island 2) was originally going to be compatible with Nintendo Wi-Fi. Also, one early screenshot showcasing a battle with Big Guy the Stilted seems to suggest that Big Guy was once going to be organic, as he had no patches on him in that picture (although one patch was visible near his right foot, which may merely mean his graphics were slightly incomplete). Finally, one screenshot of an unknown origin shows a Black Yoshi traversing a flowery area with Baby Peach. The particular event illustrated in the picture doesn't seem to be left in the final game. Baby Peach's cry was also going to sound more adult- like.
Beta-boxart of Yoshi's Island DS. Notice the name (Yoshi's Island 2) and this boxart's Wi-Fi logo; Wi-Fi compatibility was later canned in this game. - Yidscreen6.jpg
A Yoshi's Island DS beta battle with Big Guy the Stilted, who lacks mechanical features here. - YIDS BetaLogo.jpg
The beta game logo.
Yoshi's Story
It seems as if Flowers were going to appear in the game, which was once called by Yoshi's Island 64.Also, Big Guys were going to appear and Bone Dragons would be purple, flesh-covered dragons rather than bony, undead ones. Finally, Stage 4-2: The Jungle Puddle was known to be much scarier, with strange bubbles and a Bone Dragon. There was also going to be a playable Brown Yoshi and Purple Yoshi. In a manner not unlike the various rumors of unlocking Luigi in Super Mario 64, there are rumors of unlocking and playing as a Purple Yoshi. All of these rumors, however, are false. [4]
The logo for Yoshi's Island 64, Yoshi's Story's original name. 
A beta-version of a Bone Dragon from Yoshi's Story. 
The beta level of Jungle Puddle.
Diddy Kong Pilot
Diddy Kong Pilot was originally the sequel for Diddy Kong Racing. However, the game focused on just flying rather than racing on the ground as well. Donkey Kong characters would be playable, and a new character would be introduced: A hillbilly looking Kong. However, after Rare was sold to Microsoft, Nintendo now owned the Donkey Kong characters, so Rare replaced them with Banjo-Kazooie characters.
- DiddyKongPilot.jpg
Diddy Kong Pilot's (or prototypical Banjo-Pilot's) intro screen. - DiddyKongPilotSelect.gif
The beta Banjo-Pilot/Diddy Kong Pilot character select screen. Note the hillbilly Kong.
Mario Party Advance
Early screenshots showed that Shroom City would be really different from what it looks like in the final version. Also, the die is replaced by a Mushroom.
- MPA BetaImage1.jpg
An early screenshot of Shroom City.
Mario Superstar Baseball
Mario Superstar Baseball was originally known as only Mario Baseball and had a different logo from the current one.
- MSB OldLogo.jpg
The beta logo.
Mario Kart Wii
The game's oringal name was going to be Mario Kart X when it was still in development. Also, the designs for Standard Kart S, Standard Kart M, and Standard Kart L were different, as well as the HUD.
- MKWiiScreenshot.jpg
The original HUD, not too different from the final.
The beta logo.
Mario & Sonic at the Olympic Games
Birdo was originally going to be a playable character in the game but appears to have been cut out for unknown reasons. Note that because her sprite wasn't finished properly, Birdo looks odd in the screenshot. Silver the Hedgehog from Sonic the Hedgehog 2006 was seen in the intro of the game, making fans believe that Silver was meant to be playable. Donkey Kong and Jet the Hawk, from Sonic Riders, have also been found to have been planned for the game.
Birdo in the game.
Wi-Fi
Many Mario games were originally going to have Nintendo Wi-Fi; however, it was taken out of some. Mario Hoops 3 on 3 and Yoshi's Island DS (known as Yoshi's Island 2 back then) were the two games that were going to have Wi-fi however got it removed. Most likely the Wi-Fi in Mario Hoops was going to be, facing off in a basketball match with another internet user. It is unknown what the Wi-Fi in Yoshi's Island DS was going to be for, possibly a Co-op mode. Mario Party DS was also supposed to have Wi-Fi.
