Pause the game and enter the following codes:

Invisibility:

Hold R1+L1 and press Square, Square, O, O, Triangle, X

Invincibility:

Hold R1+L1 and press Triangle, Triangle, X, X, Square, O

All Inventory:

Hold R2+L2 and press X, Square, O, Triangle, Square, O

Reset Health:

Hold R1+L1 and press X, O, Triangle, Square, X, O

Reset Magic:

Hold R1+L1 and press Triangle, O, X, Square, Triangle, O

All Power-Ups:

Hold R2+L2 and press Triangle, O, Square, X, Triangle, X

Level Skip:

Hold L1+L2+R1+R2 and press Triangle, X, Square, O, O, O