Unlockables:
Activate the following cheats by entering the corresponding sequences of buttons at "Extras" > "Cheats".

All Mini Games - right, up, right(2)
Level Select - right, up, left, right, up, right
Unlimited Enchanced Vision - left, right, up, down
Unlimited Gas Mines - right, left(2), up, down, right
Unlimited Ground Pound - right, up, right, up, left, down
Unlimited Invulnerability - down(2), up, left
Unlimited Laser Eyes - left(2), up, right
Unlimited Stealth Camo - left, down(3)
Unlimited Superbar - right, left(2), up, down, up