Enter the following cheats while the game is paused.
Level Skip: Simultaneously press and hold L1 and L2 for 10 seconds. While holding the buttons, press Left, [Triangle], [X], Right, [Circle], [Triangle], Down. A level-skip option will appear on the pause menu. To skip to the next level, highlight Skip Level and press [X].
Unlimited Health: Simultaneously press and hold L1 and L2 for 10 seconds. While holding the buttons, press Down, Right, Left, [Triangle], Right, Down. A health option will appear on the pause menu. To refill your health meter, highlight Health and press [X].
Unlimited Ammo: Simultaneously press and hold L1 and L2 for 10 seconds. While holding the buttons, press [Triangle], Left, Left, Left, [Circle], [Triangle], Down. An ammo option will appear on the pause menu. To get more ammo, highlight Ammo and press [X].