Level skip:
Hold R1 + R2 + L1 + Select, and press X, Circle, Square, Triangle, X, Circle, Square, Triangle during game play. If done correctly, you will automatically win the match.

Pause in multi-player mode:
Since the game does not have a pause option in the multi-player mode, simply press Start , highlight "Quit" and press X. Your game will be paused, but it will not quit unless you select "Yes". To resume the game, select "No".

Hint: Rocket jump:
Pick up a Rocket Launcher and switch to it, then point your gun straight down. Jump, and when you are at your highest point, quickly fire the Rocket Launcher. If done correctly, your character will go high in the air. Note: You will most likely lose a little bit of health while doing this, so be careful.

Hint: BFG jump:
This works similarly to the rocket jumpm except it sends you higher. Aim the BFG at the ground, jump, and at the highest point of the jump, shoot down. You will rocket into the air. Note: You will get hurt slightly. If done on a spring pad, you will jump higher.

Hint: Special item:
If you hear a sound similar to the wind during game play, this is a sign that one or more special items have just appeared. Special items include Quad Damage, Double Damage, Haste, Double Haste, Invincibility, Mega Health, etc.

Hint: Bonus characters and level:
Successfully complete the game in campaign mode under the "I Can Win" difficulty setting. A bonus level and two more characters will appear after the credits. Successfully complete the bonus level to unlock it and the new characters in multi-player mode.