Enter the options menu and select the "Game Settings" selection, then press Left, Right, L1, L2, R1, R2, Square, Circle. If you entered the code correctly, you will hear a sound. You can now toggle cheat mode from the "Game Settings" menu. Activating cheat mode gives you all weapons with maximum ammunition and reserve ammunition, two large medical packs, and maximum experience. Alternatively, successfully complete the game on the medium or higher difficulty settings and save when prompted. Select "Game Settings" on the options menu, and enable the cheats. Load or start a new game to begin with 999 ammo, all weapons, and all combos. -From: gizmogreen.net and jeffield.net.au