At the title screen press Down, Down, Up, Down, Left, Right, Down, Up, Up, Up, Right, Left, X
Hyper extended fighting
At the title screen press Left, X, Up, Y, Right, B, Down, B
Large world map critters
At the team fighter creature select screen press L, L, Down, Down, Black, White, Black, White, R, L, Black, R, R, R, White
Team fighter mode character variations
At the creature select screen in versus mode press L, L, Down, Down, Black, White, Black, White, R, L, Black, R, R, White
Versus mode character variations