World 4 (New Super Mario Bros.)
World 4 is a secret world in New Super Mario Bros.. If Mini Mario or Mini Luigi defeat Mummipokey in World 2 they will go to World 4 instead of World 3.
World 4 is a giant forest with many enemies like Wigglers. Also, much of the water here is so polluted that it eminates an eerie purple color and grants instant death, regardless of what form Mario/Luigi is in (even in Mega form). Bowser Jr., like in every world, is fought here, and a Ghost House is also located here. Mega Goomba is the big boss of this world.
4-1
In this level, strange purple goop covers the ground. If Mario touches it, he will instantly lose a life. To start, Mario should keep walking until he finds some Scuttlebug. He should jump on them to gain a jumping boost, which is used in collecting the first Star Coin. About halfway into the level, the player should see a Dorrie. Jump on it to ride it, while avoiding the Scuttlebugs. To get the second Star Coin, Mario again should get a jumping boost from the Scuttlebug. After getting off Dorrie, Mario should jump onto the donut lifts to avoid falling into the goop. The final Star Coin can be obtained by using a Koopa Troopa and throwing the shell at the coin. After this, Mario reaches the Flagpole.
Secret Exit
While Mario is riding Dorrie, the player should notice that on the way, there are two ? Blocks with three normal blocks in between. If Mario gets on top of them and jumps in the middle, a Beanstalk will appear. Climb on it and enter the pipe to reach the Red Flagpole. The secret path opens up a Toad House and takes the player to 4-Tower.
4-2
This level has purple mushrooms that, when Mario stands on them, tilt to the side he's on. Move quickly to avoid falling off of them. The first Star Coin can be obtained by Wall Jumping to it. To get the second Star Coin, Mario must let one of the purple mushrooms tilt to the right. Once the player gets it, jump off to the next mushroom. Soon after the coin is a Red Coin Ring. Mario will come to a stepped platform. Jump on the purple mushroom after it, let it lean to the left, and jump over to the brick and hit it to reveal a Beanstalk. Climb it to go to a bonus area. Go up to find the third Star Coin. Then the player should go through the Warp Pipe and get to the Flagpole, ending the level.
4-3
This level takes place underwater. Go into the pipe and start swimming. Soon, the level will start auto-scrolling. Maneuver through the water while avoiding the Regular and Mega Unagi. The first Star Coin is in a little crevace about a quarter into the level. After the coin is a Red Coin Ring. The second Star Coin is found about halfway into the level between two Unagi. If the player presses the ? Switch and then goes into the green pipe that is next to the yellow pipe, they will find the final Star Coin. After going through the Exit Pipe, Mario will reach the Flagpole.
4-Tower
This level is filled with lava. Mario should jump on the moving gray blocks to get to the door. In the next area, lava rapidly rises. First, get on the other side of the metal fence. If the player stays to the left, he/she will eventually reach the first Star Coin. The second Star Coin is in between a few Amps. Next, Mario should avoid the spikes, and continue climbing. If Mario stays to the right, then he'll find the last Star Coin. A Red Coin Ring is found near the end of the level. This time, Bowser Jr. will be harder to defeat. If the player tries to jump on him, he'll go inside his spiky shell. Wait until he throws a Green Shell. Then, Mario should jump on the shell to stop it, and he should throw it at Bowser Jr., which stuns him. Only then can Mario jump on him. Doing this three times will defeat Bowser Jr.
4-A
This level has more purple goop in it. To begin, Mario needs to swing on the vines in order to get to each platform. The player should soon see a Pinwheel (YI), and then he/she should use it to again jump onto land. When Mario finds a Paratroopa in the way, jump on it to get a boost. Use this skill to get the first Star Coin. This is also used to reach some faraway ledges. To get the second Star Coin, use a Paratroopa to bounce up to a vine above him. Swing into the Warp Pipe to reach a cave with the Star Coin inside. The player should notice three pipes together (green, yellow, green). Enter the lowest one to get the third Star Coin, after this, Mario reaches the Flagpole.
4-4
This level features a lot of Wigglers. Mario can complete the Red Coin Ring by getting a boost from a Wiggler. The first Star Coin is found in a little cave near a Wiggler. Later, Mario needs to hit a block that contains a Beanstalk to climb up it and continue. If the player goes left and Wall Jumps off the wall, they will find the second Star Coin. The last Star Coin can be obtained by sliding on a wall next to it, then Wall-Jumping to the small pipes. After going through the Yellow Pipe, Mario reaches the Flagpole.
There is a very secret area in this level, reached by using a Mini Mushroom to go down one of the small pipes - the second from the left where four are together, with a Wiggler on top. This secret area has a Mega Mushroom, and a lot of pipes to smash, along with some coins to collect.
4-Ghost House
To start, Mario should step onto a striped platform that takes him past a wall. The first Star Coin can be found by going up past the blocks and right to another striped platform where he will find the coin above it. After the platform, Mario should press the ! Switch and go through the door, avoiding the Balloon Boo along the way. To get the second Star Coin, Mario should press another Wall Jump on the first red blocks he sees (for the third Star Coin, see "Secret Exit") and go up. Then, the player needs to jump on the blocks, past the first door (if Mario goes through the first door, it will take him back to the start of the area), and into the second door. This will take Mario outside, to the Flagpole.
Secret Exit
To access the Secret Exit, the player needs to be Mini Mario. When Mario reaches the area with the second Star Coin, Mario should get onto the pipe, not entering it. Then, he should Wall Jump on the pipe, reaching a faraway door. By continuing to Wall Jump and by going up, Mario will reach the third Star Coin. Going through the door takes Mario to the Red Flagpole.
4-5
This level is an underground level with Bob-ombs. Some bricks can only be destroyed by blowing up a Bob-omb. This is needed for Mario to get past some areas. This skill is also used to get the first Star Coin. To get the second Star Coin, the player must wait until a drawbridge goes up. Next, he must hit the Bob-omb above him, destroying some blocks, allowing him to get the coin. After a few more drawbridges, the player should notice one that has a pipe with blocks covering it. If Mario blows up a Bob-omb, he can go inside it and, by breaking more blocks with Bob-ombs, he can get the last Star Coin. Leaving the Warp Pipe is the Flagpole.
4-6
In this level, Mario will ride another Dorrie, avoiding yet more purple goop. To get the first Star Coin, Mario should jump onto land, past the Red Coin Ring. When on land, the player should keep up the pace with Dorrie. The second Star Coin is obtained by pressing a P-Switch and jumping on it. Soon, the player should see a! Switch. Mario should wait for Dorrie's head to go up, and then he should jump and press the switch so he can go into a pipe that contains the final Star Coin. Soon, Mario should reach the Flagpole.
4-Castle
The player will start off on a ledge. They will see a platform that will swing from left to right, along with a ? Block containing a coin. The player will see coins floating in the air, aswell as another ? Block, this time containing a power-up. The player will now have to jump on another swinging platform, which will have a Dry Bones wandering on it. A Podoboo and another swinging ledge with a Dry Bones can be seen. If the player jumps when the swinging platform is at it's max height, they will get their first Star Coin. The player will fall down, and see a Dry Bones along with two ? Blocks, containing coins. Now the player will see a couple of Thwomps. The player can take two routes from here, either Wall Jump while collecting coins, or jumping from platform to platform while avoiding a Thwomp. In the lone platform, there is a Hidden Block with a Star inside of it, along with two visible one's containing coins. The player will see a couple of Dry Bones and a Super Thwomp. If the player waits while the Super Thwomp is crushing the blocks, they can get their second Star Coin. The player will find a ? Block, containing a power-up. The player will meet up with more Thwomps and Dry Bones, aswell as another Super Thwomp. The player will collect some coins and find a Dry Bones here. The player will now be at the checkpoint area, and see a ? Block containing a power-up, a Podoboo, and another ? Block which will have a 1-Up Mushroom. The player will be on a swinging platform, and see their last Star Coin.. The player must jump from the swinging platform to another, while avoiding a Dry Bones and many Podoboos. The player will now see a boss Door, and will fight Mega Goomba. After the player has defeated it, they will now have access to World 5 (NSMB).
Enemies Introduced
