Cheats for Ready 2 Rumble Boxing (GBC)

Hightlight Arcade mode, then enter the codes.

Unlock Damien Black
Right, Left, Right, Right, Left, Left, Right, Right, Right, Left, Left, Left

Unlock Kemo Claw
Left, Left, Left, Right, Right, Right, Left, Right, Left, Right

Unlock Nat Daddy
Right, Right, Right, Left, Left, Left, Right, Left, Right, Left