"These two cabinets are the only copies of this game that exist. If they were to ever stop functioning, Marble Madness II will be lost forever. They did some location tests for it, but it wasn’t very popular because they were trying to release it in the middle of Street Fighter II's heyday, so they didn't bother.”
This is a terrible shame. As a fan of the original Marble Madness, I would love the chance to play the sequel.