The 3DO M2 is one of the most famous unreleased consoles of all time.
A successor to the ill-fated 3DO Interactive Multiplayer, the M2 promised the kind of power that would put the Saturn and PlayStation in the shade – but in 1996, 3DO sold the rights to M2 to Panasonic's parent company, Matsushita, which ultimately cancelled the project the following year.
The M2 did make it to market as a physical product, however – the FZ35-S was a kiosk-style unit intended for commercial purposes. As explained by the 3DO Archive, it featured the same hardware as the M2, but was incapable of playing the games which were powered by the arcade variant of the M2 hardware.
Thanks to the efforts of Dutchconsolefreak / @Clown57859, it's now possible to play an M2 arcade 'port' on a FZ-35S kiosk system – and it's Konami's 1998 one-on-one fighter, Battle Tryst.
The game is notable for the fact that it was originally intended to include fighters based on Castlevania's Simon and Richter Belmont.
Konami released four other games on the M2 arcade standard: Heat of Eleven '98, Evil Night, Tobe! Polystars and Total Vice.