At the screen where Exor bellows "Midway presents WARGODS!!"
press Right, Right, Right, B, B, A, A.
At the character select screen press Left, Down, Down,
Right, Left, Up, Left, Up, Right, Down
At the character select screen press Down, Right, Left,
Left, Up, Down, Right, Up, Left, Left
At the title screen press C left ,C left, R, A, B, C up, C right