Master Control Debug Menu
Most game companies, as they are debugging their games, create a Debug Menu to allow them to access remote situations in the game without playing completely through the game.
In SSBM, this menu allows
near complete freedom in a multiplayer setup, including using player like Giga Bowser, Sanbag, Master/Crazy Hand, and the Wireframes, and playing on nearly every possible level in the game.
It also allows you to mess around with settings that only Nintendo could use before.
A FAQ on the Global Data Edit under the Debug Menu can be found
here.
