Max Power Specials:
Select "Secret Options" at the "Options" screen, and then while holding SELECT enter the following:
square, X, R1, circle, up, square, down, up, down, X, square

Powerful Artificial Intelligence(opponent only):
Select "Secret Options" at the "Options" screen, and then while holding SELECT enter the following:
circle, up, triangle, circle, left, triangle, square, square, x, down

Fuzzy Mode:
Select "Secret Options" at the "Options" screen, and then while holding SELECT enter the following:
triangle, circle, right, triangle, up, right, circle, up, square