Batman and Robin
Easy Clues
Whenever you need a clue go to a store called "Bookworms". You can break into here whenever the lights are on. You can almost always find clues and powerups in here.
Invincibility
At the Title Screen press L1, R2, R1, L2, Select, X, Circle
Limited Invincibility
For Limited Invincibility press Circle, Circle and a yellow bar will appear. You will have limited invincibility until that yellow bar runs out.
Super Health