Pitfall: The Lost Expedition

Bottomless canteen
Hold L + R, then press: Left, B, X, Down, B, A, B, X.
(Thanks to thundergirl@yahoo.com)

Hyper Punch Mode
Hold L + R, then press: Left, Right, X, Up, X, Right, Left.
(Thanks to thundergirl@yahoo.com)

Original Pitfall
Hold L + R, then press: X, X, Left, Right, X, B, A, Up, X.
(Thanks to thundergirl@yahoo.com)

Play as Nicole
Hold L + R, then press: Left, Up, Down, Up, X, Up, Up.
(Thanks to thundergirl@yahoo.com)

Unlock Pitfall II
Collect and use all Idols.
(Thanks to thundergirl@yahoo.com)