Super Cheats
At the title screen, hold A, B and C on both Controllers while pressing Start on nController one. You should hear a chome. Next, start the game. Press A while the game is paused, and your health meter will ne refill when you unpause. Pressing B while the game is pause will give you partial invincability. Press C while paused to see the number of the current stage, which can be changed by pressing Left or Right on the controller pad. Change to a different stage number and you'll be warped directly to that stage when you press the Start button