Cheat mode:
Win the these modes to unlock the cheat options: Challenger Mode, Defender
Mode and Champion Mode.
You can now select Itchy, Scratchy, Kodos, Kang, Burns, Smithers and
select the stadiums you want to fight in.

Extra wrestler:
Complete all three modes of the game. Now you can play as Itchy & Scratchy for one level, Kang for
another level, and Smithers for another level.

Wrestle as Bumblebee Man:
Complete new challenger circuit mode and you will eventually fight Bumblebee Man. Defeat him and
save
so you can unlock him at the character selection.

Wrestle as Moe:
Complete new challenger circuit mode and you will eventually fight Moe. Defeat him and save
so you can unlock him at the character selection.

Wrestle as Professor Frink:
Complete champion circuit and fight Professor Frink.  Defeat him and save
so you can unlock him at the character selection.

Wrestle as Ned Flanders:
Complete champion circuit and fight Ned Flanders.  Defeat him and save
so you can unlock him at the character selection.

In-game reset:
While in game pause the gameplay. Hold Start and Select at the same time.