Level Skip:
     While playing, hold R and press B, B, B, X. Release R then hold L
and press Y, Y. Release L then hold R and press B, B.

Sword Upgrade:
     While  playing, press pause then hold L + R and press X, B, X, Y,
Y, B, X, B.

Big Heads:
     While playing, hold R and press Y, Y, Y, Y. Release R then hold L
and press Y, Y. Release L then hold R + L and press Y, X, Y.