The eight-hour long footage you see above is of Xbox 360 game Gears of War 3 running on a PS3 devkit. The description explains that this version is dated May 19, 2011, and is the only build of this ever located. Following lots of speculation, Epic Games has now revealed the reason for its existence.
While even Gears of War 3 design director Cliff Bleszinski initially thought the footage might be fake, Epic revealed to Kotaku in a statement that it was indeed real, and was simply used for testing:
"This footage is a byproduct of Epic's internal Unreal Engine 3 testing process, which utilized both Gears and Unreal Tournament, and was never part of any actual product work for PS3."
This particular build of Gears of War 3 is almost playable from start to finish, although a couple of the levels don't work properly due to scripting and checkpoint issues. Interestingly, it also apparently tries to read storage like it's running on an Xbox 360, and if you select a profile it softlocks the system. Fascinating stuff!
What do you make of the footage above? Let us know your thoughts on Gears' PS3 build in the comments.