Marble Madness II - Undumped Prototype?
It seems that somebody got a hold of an undumped Marble Madness Atari arcade game and did the right thing: they dumped and released the roms for the world to see. This is how you do it folks. You don't sell the roms to the highest bidder. https://www.techspot.com/news/94736-unreleased-atari-game-marble-madness-ii-leaks-online.html