It really depends how far down the rabbit hole you want to go. You also get into label variants like gun.smoke, blue/black untouchables, MTPO vs PO, silver/yellow Metroid, game revisions like tecmo bowl and tecmo NBA basketball where they actually took characters out or added new characters, the 4 different variants of Wayne Gretzky, then you also have some games like Hollywood squares where there's a blue and a black box but no different cart and flying dragon that has variant manual and boxes but not carts. I can try and find my list for you this weekend if you don't get one before. There's also a couple label variants for unlicensed tengen Pac-Man.