Allow two players to select the same character:
At the title screen, press Down, R1, Up, L1, Triangle, Circle.
Begin the level with the Power of Love Sword:
At the title screen, press Square, Square, Square, X, Circle, X, Triangle.
Changes coin sprites into animal sprites:
At the title screen, press Up, Up, Down, Down, Up, Up, Up, Up.
Enables Blood Mode:
At the title screen, press X, Circle, X, Square, X, Circle Circle.
Unlock Zombie Mode:
At the title screen, press Down, Up, Right, Down, Up, Right, Down, Up, Right, Right, Right.
Unlock Sound Check Bonus Level:
At the pause screen in Score Ranking Overworld, press L1, L1, L1, R1, R1, R1, L1, R1.
Beat the game with all four characters.
Unlock Mr. Chou:
Sometimes after a stage, you'll see Mr Chou on a random level, go to that stage and you'll fight him. Beat him to unlock him.
In the first level after the shopping district near the underground car tunnel, there will be a star on the wall. When you approach, a hidden doorway will open, this shop has some of the best items in the game.
Unlockable Video Rewards:
If you pay off your $500 fine at the video store, you can purchase the following items for $4.95:
The Mystical Head: Extra life, maximum of nine.
Seven Shaolin Masters: Gives +100 XP, +10 DEF, +10 SPD, +10 WP, +10 STR.
Alien VS T-Rex: Gives +20 STR.
Alone and Disturbed: Gives +1,500 experience points.
I Love Your Boyfriend: Gives +320 XP, +15 DEF, +15 WP.