The following should also be 4-way (besides the ones Krajkerjac mentioned): Mr. Do, Mr Do's Castle, Dig Dug, Dig Dug 2, Burgertime, Crush Roller, Lady Bug, Jumping Jack, Qix, Pengo, Space Panic, New Rally-X (this one sucks on this board, since it's a horizontal game), Tank Battalion, Van Van Car and Amidar. I'm sure there are others too, but those I know should be 4-way. You should also be able to play the following 2-way games: Space Invaders, Galaxian, Galaga, Phoenix, Pleides, King and Balloon, Mappy, Moon Cresta, The End, and Pooyan (up/down)