Enter the following at the title screen:
Bottomless canteen:
Hold L + R and press Left, X, B, Down, X, A, X, B
Classic Pitfall game:
Hold L + R and press B, B, Left, Right, B, X, A, Up, B
Hyper punch mode:
Hold L + R and press Left, Right, B, Up, B, Right, Left
Play as NICOLE:
Hold L + R and press LEFT,UP,DOWN,UP,B,UP,UP