Big Head Mode
To enable Big Head Mode, make the name of your fighter DAVID TUA.

Dumb Mode
To make all of the boxers a whole lot dumber, start the game with a fighter named JESSICA MELTON.

Farting Boxers
To make all the boxers fart, name your fighter ADAM GARDNER.

Fat Mode
To enable Fat Mode, enter your fighter's name as RICH OBERDICK.

Invincibility
To become invincible, name your fighter MUHAMMAD ALI.

Unlock All Arenas
To unlock all arenas, enter LENNOX LEWIS as your fighter's name.

Unlock All Boxers
To unlock all boxers, enter MIKE TYSON as your fighter's name