Invincibility:
Hold Option 2 + Option 1 (in order), and press Up/Right at the title screen after the Slime World logo falls. Release all buttons and begin game play. Note: The game may crash in multi-player mode when this code is enabled.
Zit popping mini-game:
Enter the screen with the green Todd that appears after the summary screens. Press Option 1 to display a zit and pop it by quickly hitting the other buttons. This game may be played in multiplayer mode.