Taz-Mania
Contributed by - Richard

Level select:
Press A, Y, A, Y, X, Y, B, A, R, L at the option screen. The screen
will shake to confirm correct code entry. The level selection screen
will appear. 

Ten continues:
Press B, A, Y, A, X, A at the option screen. The screen will shake to
confirm correct code entry. 

Twenty continues:
Press Y, X, B, X, A, X, L, R, A, X, A at the option screen. The screen
will shake and the number "20" will appear below the "Options"
selection to confirm correct code entry.