There are several button combinations that can be used to instantly unlock some of the features of the game.
Unlock all Puzzles in Puzzle University
At the title screen, hold and press , , , , , , , .
Unlock Very Hard difficulty setting
At the title screen, hold and press , , , , or complete the game under the Hard difficulty setting.
Unlock Super Hard difficulty setting
At the title screen, hold and press , , , , or complete the game under the Very Hard difficulty setting.
Game speed over 50 in marathon mode
At the title screen, hold and press , , , , or earn 10,000 points in the time zone.
Unlock All Trainers
At the trainer select screen, hold on controller 1 and simultaneously press and on controllers 1 and 2, or complete Spa Service.
Play as Mewtwo
At the trainer select screen, hold on controller 1 and press , , , , , , , , , or complete the game under the Super Hard difficulty setting. Note that Player 2 will always be Mewtwo, while Player 1 is always Ash.