Level skip:
Press Start to pause game play, then press Up, Down, Left, Right(2), Left, Circle.
Level select:
Save the game and return to the main menu. Select the "Resume Game" option, then highlight the previously saved game and press Up, Down(2), Up, Left, Up, Right, Down.
Invincibility:
Press Start to pause game play, then press Square, Circle, Left, Right, Circle, Square. Alternately, press Start to pause game play, then press Square(2), Circle(2), Left, Right, Circle(2), Square(2).
Full ammunition:
Press Start to pause game play, then press Left, Right, Circle(3), Right, Left.
All characters:
Press Start to pause game play, then press Left(2), Circle(2), Right, Left, X.
All weapons:
Press Start to pause game play, then press Left, Circle, Right, Square, Right, Left.
Fatboy Mutator:
Press Circle(3), Up, Down(2), Up, Circle(3) at the main menu. Select multi-player mode and choose the Fatboy Mutator. Get killed to have the new Mutator get thinner. Get a kill to have the Mutator get bigger.
Stealth Mutator:
Press Square(2), Circle(2), Square(2), Circle(2) at the main menu. Select multi-player mode and choose the Stealth Mutator.
Big head mode:
Press Left, Right, Left, Right, Left, Right, Circle(3) at the main menu. Select multi-player mode, highlight the "Mutators" option and press X. Highlight the new "Big Head" option, then press Right, X.
Firewire multi-player mode:
Note: This trick requires a four port Firewire PC hub. Use Firewire cables to connect the iLink port of one to three more PlayStation2 consoles to the hub. Press Start to pause game play in two player multi-player mode and press Left, Circle, Left, Right, Square, Right. Have all players press Start at the waiting screen.
Hint: 999 Redeemers:
Enable the "Invincibility" code when in the Face's Of World level for capture the flag. Get the Redeemer from top of either castle. They are found on the left hyper link. Then enable the "Unlimited ammunition" code to get 999 Redeemers. Fall out of space and you will not die. Just press R2 to shoot the controllable rocket, then try to see how many people you can trace and kill -- but get the other team's flag first.
Hint: Additional levels:
Successfully complete the game under the inhuman difficulty setting to unlock 7 death match and 4 capture the flag levels. No additional two player levels will be unlocked.
Pause the game in two player multi-player mode.
square,right.Then have all players press Start at the waiting screen.