All FMV
     Pause the game. Hold down L and R, then press 3(B), 3(X), B, X,
B.

All Powerups
     Pause the game. Hold down L and R, then press X, B, X, B, X,
3(B), 2(X), B, 3(X).

All Warp Gates Open
     Pause the game. Hold down L and R, then press 2(B), X, 2(B), X,
B, 3(X).

Credits
     Pause the game. Hold down L and R, then press B, 2(X), B, X, B.

Holiday Easter Eggs
     If you game clock is set to one of these holidays, neat stuff
happens:

December 25th: Snow 
January 1st: Fireworks 
October 31st: Bats 
July 4th: Fireworks