Invincibility:
Hold L1 + R1 + L2 + R2 and quickly press Left, Right(2), Circle, Square during game play in endurance mode.

Weapon eject:
Hold L1 and press X(2), Square during game play.

Shield:
Enable the "Instant Combo" option at the cheats screen. Then, hold R1 and press Triangle, Square, Triangle, Square during game play. This code may be repeated to increase its effect.

Buzzsaw:
Select the hard or very hard difficulty setting. Win Eliminator, Deathmatch, and Endurance ranks with the same character.

City Canal level:
Successfully complete the Deathmatch level under the normal difficulty setting to unlock the City Canal level in multi-player and quick battle modes.

Downtown level:
Successfully complete the Eliminator levels under the normal difficulty setting to unlock the Downtown level in multi-player and quick battle modes.

Santa hats:
Set the system date to December 21 through December 25.