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.
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.
10 Lives
Press Start to pause the game. Then press Left, Select, Right, Select, Left, Select, Right, Select. Repeat until you have 10 lives.
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.