Cool game, great 3D effect. Sold mine a while back to get one of my grails. I made a free-play rom of sorts (IM me, and I'll send it)...requires a jumper wire from START button to credit...press START to credit and go to "PRESS START" screen (START button will flash), press START a second time to clear credit and start game...a kludgy method, but allowed me to keep the attract mode, and not get stuck in an endless loop if it were the jumper wire alone...the "rom" adds the words "FREEPLAY" to attract mode, passes the power-on self-test, and credit/starts the game when START is pressed.