Use the following cheats at the main menu:
Master Cheat: L, R, L, R, X, X, Y, Y
Unlimited Handcuffs: X, Y, X, Y, L, R, R, L, L
120 Achievement Points & power moves: L, L, R, R, L, R, L, R
Unlimited Batlaunchers: Y, X, Y, X, L, R, L, R
All Movies: L, L, X, X, Y, X, L, R
Unlimited batrings: L, R, Y, X