Various cheats

Large world map critters 
     At the title screen press Left, X, Up, Y, Right, B, Down, B

Versus 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

Hyper extended fighting 
     At  the  title  screen  press  Down, Down, Up, Down, Left, Right,
Down, Up, Up, Up, Right, Left, X

Team fighter mode character variations
     At  the  team  fighter  creature  select screen press L, L, Down,
Down, Black, White, Black, White, R, L, Black, R, R, R, White