Challenge (New Super Mario Bros.)
The Challenge mode is a secret, harder game mode in New Super Mario Bros. It has a few different block locations and does not allow the player to scroll the screen backwards, similar to the older Mario games such as Super Mario Bros. and Super Mario Land. The Challenge mode can be accessed in the start menu after finishing the game and pressing the following buttons: 
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In terms of screen-scrolling, there are some exceptions. If the Challenge mode is enabled on a level that requires the player to go backwards, the screen will not scroll down instead. If it is enabled on a level where the player must move in all directions, the screen will scroll normally in some or all of the sections of the level. The levels that cannot be played in the Challenge mode at all include World 2-3, World 5-
Tower, World 5-
Ghost House, World 5-4, World 7-7, and World 8-
Bowser's Castle.
The Challenge mode can cause several glitches in the game. For example, if the player jumps in the small space between a wall and the left edge, the player will float. If the player repeatedly jumps and wall jumps from that location, the player can go over certain parts of each level. If there is a ceiling above the player while doing so, the player will get stuck in the ceiling and be pushed away from it.
