Originally an Xbox One launch exclusive, Ryse: Son of Rome hit Steam in 2014. It was an impressive technical showcase for a new console, but was in every other way mediocre, a sadly common fate for games with such long gestation periods. Originally revealed as Codename: Kingdoms during Microsoft's 2010 E3 conference, the Crytek developed game was later revealed to be a Kinect-only Xbox 360 title. After a long period of absence, Microsoft re-announced it in 2013 as a third-person action game for Xbox One. That's the version we got.
But in-between all that stuff, it was a first-person Xbox 360 action game that didn't require Kinect, and thanks to an early prototype found on an auctioned Xbox 360 dev kit, we can see what might have been. The video embedded below is courtesy of Prototype Preservation, a channel which acquired a copy of the build from Twitter user @cheese93007 (thanks Eurogamer).
Leaving aside all the placeholder stuff (the fact that the enemies are all identical is the biggest illusion breaker), this version of Ryse looks promising. First-person melee combat isn't everyone's cup of tea, and the cutscenes are laughably melodramatic, but one can easily imagine a more polished version of this demo wowing E3 audiences.
Check out the video here: