In the extras menu under cheats, then choosing "Enter cheat code" and entering.

Password	Effect
456645	Damage boost
313456	God mode
118147	Unlimited lobber goo
971238	Unlimited scatter goo
854511	Unlimited splitter goo
691427	Unlocks Exo-Huggles 9000 for play
654168	Unlocks Mr. Huggles for play