10 Lives:
Press Start to pause the game. Then press Left, Select, Right, Select, Left, Select, Right, Select. Repeat until you have 10 lives.
Go Go:
Pause the game, then press B, B, B, B, B, B, B, B. YOU WILL BE ABLE TO GO ANYWHERE ON THE LEVEL!!! Press A to appear.
Invincibility:
Pause the game and press: a, a, x, a, left, right, right, left.
Life Refill:
Press Start to pause the game. Then press X, Select, X, B, X, Select, X, A. After the code has been entered, a noise will confirm that it worked. Press Start again to refill your life.
Pause Trick:
Press Start to pause the game. Press A eight times. The Pause screen will no longer darken, allowing you to plan out your next step with some detail.
Stage Skip:
Press Start to pause the game. Then press Select, B, X, A, A, X, B and Select. After the code has been entered, a noise will confirm that it worked. Press Start again to skip to the next stage.