Kick Them When They're Down
Press START when you win a round. You can now walk around and beat up the character on the floor.
To disable Gems in two player mode both players must press and hold START after choosing their character until the round starts.
Change Character Color
At the character select screen move to the desired character then hold U (if on top row) or D (if on bottom row). After three seconds press any P or K button to select character.
To select the hidden characters below you must have a Japan game board (on freeplay) and access to the machines credit switch.
Press and hold the credit switch. Press START and at the character select screen use the following moves to select characters.
Anita - MP, LP, L, LK, MK.
Dr. Doom - MK, LP, D, LK, MP.
Thanos - LK, HK, MP, MP, UP.