This is not some fan game made to play like Marble Madness, but the real deal, a legendary lost prototype from the Silver Age of Atari Games! Cancelled because of the great arcade fervor at the time around fighting games, meaning little Atari released in that era performed well on test.
Word is that the rom has been released somewhere on the internet, although I do not know where. It had been known that all the surviving Marble Madness II cabinets were owned by old Atari staff or collectors who were averse to allowing the rom images to be released. Whether one of them had a change of heart or, as has been speculated with Akka Arrh, another legendary prototype, they may have been obtained through nefarious means.
Technically the rights are still owned by Warner Media, I believe. I’ve long been amazed that the current rights holders haven’t seeked out the owners of these prototypes and offered them a big payday to dump the roms and release something like a Midway Arcade Treasures 4. Sure, it’d only be a matter of time before someone broke the roms out of such a package, but they’d still sell a ton of units and the prototype owners would be properly rewarded for both maintaining their machines and for lost collector value, and importantly, the games would be out there among people who would enjoy them and be protected against further loss and obscurity.