Go to the Cheats screen of the Setup menu and press START, Z, A, Y, X, Z, Z, Z, START.

To unlock boxers the hard way, do the following:

• King Khan: Beat Top Contender Tournament.
• Matador: Beat Intercontinental Tournament.
• Odiva: Beat Pro Tournament.
• Old Master: Beat World Championship Tournament.
• Training Robot: Complete training mode.

Go to the Setup screen, then Cheat Codes. Enter this code to activate the cheat: START, A, Y, X, X, Z, Z, X, Y, A, START.

Go to the Setup screen, then Cheat Codes. Enter this code to activate the cheat: START, A, A, Y, Y, Z, Z, X, X, START.

Go to the Setup screen, then Cheat Codes. Enter this code to activate the cheat: START, A, A, A, Y, Y, Y, X, X, X, START.

To have a constant stream of power-ups, go to the Cheats screen of the Setup menu and press START, A, Y, A, Y, A, Y, X, X, X, START.

Go to the Setup screen, then the Cheats menu. Press START, A, Z, Y, X, START to enable the cheat.

To unlock Life mode for all of the boxers, go to the Cheats menu in the Setup menu and press START, A, X, Y, Z, A, X, Y, Z, START.

To unlock the Scrap Yard, go to the Cheats screen of the Setup menu and press: START, Y, Z, Y, Z, A, A, START.

Press START, Z, Z, Z, Z, Z, Z, Z, Z, Z, Z, START on the Cheat Menu.