At the title screen, put in:
Unlock all cheats: L2, R2, L2, R2, Square, Square, Circle, Circle
All Power Moves: L1, L1, R2, R2, L2, R2, L1, R2
Unlimited Handcuffs: Square, Circle, Square, Circle, L2, R2, R2, L2
Unlimited Batlauncher: Circle, Square, Circle, Square, L1, R1, L2, R2