Fourth Of July Mode:
Set the system date to July 4 to unlock Homer in his car. Press L and he will shoot fireworks out the window.
John McCarthy: Win UFC mode as Bruce Buffer.
Bruce Buffer: Win UFC mode with all characters.
Mario Yamasaki: Win UFC mode as John McCarthy
The Cat: Win four consecutive matches in arcade mode.
Femme Fatale: Win eight consecutive matches in arcade mode.
Ice-T: Win sixteen consecutive matches in arcade mode.
Mask: Win twenty seven consecutive victories in arcade mode.