At the ''Beware'' screen, press A, Left, U, C, A, Right, Down. The screen border turns white if entered correctly. While playing the game hold down A and press Start, Start to fill your health and get 99 lives.
Level Select
When the battle screan appears press DOWN, RIGHT, A, C, UP, LEFT, A. You should hear a laugh if you do this correctly. Do this three times then start the game. To skip levels press START and look in the upper left corner where the score is, this is where the level number will appear choose a level and press START to go there. Note: Level 1 is the end of the game, not the beginning.