Well Scott Pilgrim is no exception to cheat codes! The codes are:
Enter at Start Screen
Zombie Mode: Down, up, right, down, up, right, down, up, right, right, right
Animal Coins: Up, up, down, down, up, up, up, up
Blood Mode: X, O, X, Square, X, O, O
Play as same character: Down, R1, up, L1, Triangle, O
Power of Love at start of level: Square, square, square, X, O, X, Triangle
Enter in game at status screen
Audio Studio: L1, L1, R1, R1, L1, L1, L1, R1, R1, R1, L1, R1