The Xbox One's flagship fighting game Killer Instinct didn't begin life on Microsoft's latest hardware, as two newly-unearthed prototype videos demonstrate.
The clips, one above and one below the break, come to us from the prototype sleuths at Past to Present Online and depict an early-in-production version of the game, when it was still in the hands of developer Double Helix. Despite using a relatively underpowered Xbox 360 as a test bed, this version of Killer Instinct retains many of the hallmarks of the Xbox One game, from its basic combo system, to character designs, to certain graphical flourishes. Granted, there are parts of the game that are obviously not finished and the Xbox One's Killer Instinct is far more littered with particle effects than its Xbox 360 predecessor, but otherwise this game is immediately recognizable.
While this demonstrates that Killer Instinct probably could work on the Xbox 360 without losing much of its core gameplay, it's most likely that this prototype was built in an era when the Xbox One hardware wasn't quite finished but Double Helix needed a way to test its new fighter. You'll notice that the game even features references to the Xbox One's Menu button, despite the Xbox 360 having no such functionality. Sorry Xbox 360 owners, but after all the money Microsoft's poured into Killer Instinct to promote the game as an Xbox One exclusive, it's unlikely to appear on any other hardware - even one of Microsoft's own machines.