Press Start to pause game play, then hold L + R and press A, B, A(2), B(2), A(2). The sound of a siren will confirm correct code entry. When the game is resumed, you will start at the current Boss.
All weapons, keys, ammo, and health
Pause the game, then hold L + R and press A, B(2), A(5). If you entered the code correctly, you will hear a shout. All weapons and keys will be unlocked, and your health and ammunition will be restored.
God mode
Pause the game, then hold L + R and press A(2), B, A(5). If you entered the code correctly, you will hear a sound.
Level skip
Pause the game, then hold L + R and press A, B, A(2), B(3), A. If you entered the code correctly, you will hear the sound of a door opening. When the game is resumed, you will start on the next level. Note: If this code is enabled on level 1, you will go to the secret floor.
Advance to boss level...