Invincibility:

At the title screen, press, Up, Down, Down, B, A, A, Down, Up, Left, B.

Unlock Race Mode:

Perform at least four good deeds. Once race mode is unlocked you can race for tokens with which you can buy the following bonuses: Chalk Mode, Crude Oil Mode, Cyber Shadows, Fast Mode, Infinite Flame, Infinite Gas, Invulnerability, Leak Mode, Low Gravity, Money For Merlin, Plastic Mode, Super Flatulence, and Super Strength.