Energy Top Up:
While playing in career mode, hold L1, R1, L2, and R2 when given the choice to hit the heavy or the speed bags between fights. Two to eight energy points will be regained, depending on how long the buttons are held.

Big Head Mode:
Big Head mode makes all the Generic boxers have huge heads. Once this mode is turned on, it will stay on in all modes until the PlayStation is rebooted. Press Left + Circle, Left + Triangle, Left + Square, Left + X. If entered correctly, you will hear a sound.

Box As A Bear:
At the main menu, press Right + Square, Right + Triangle, Right + Circle, Right + X. If entered correctly, you will hear a sound. Then select any boxer to play as a bear.