Quantum Theory is innovative in original in one aspect: it asks where plagiarism stands in game development.
Normally, I hit others upside the head that say one game copies another, but I couldn't agree more this time. This game try to hard to be Gears of War, and takes out anything fun that game, keeps all the frustrating parts, and makes Gears, awkwardly, less appealing just because of this game. This is the extent of the plot got (or cared for): you play as Syd, a soldier defending Earth from creatures that rise from the ground to kill humanity ( I think the Locust want their plot device back). The 3 or so faceless companions of yours gets axed, and you must now destroy these strange towers with a girl that kicks more ass then you can, oddly enough. The voice work in this game won't win awards any time soon, because they're delivered in the dumbest of ways, such as "Yeah, breaking stuff always works" in a voice that only reminds you of Marcus Fenix.
The game took around 4 hours or so to finish and that was on the hardest difficulty there was. Any lower the game would've been playing itself. Even the controls of the game are like Gears, except without the active reloads or general fun to be had. Whenever an enemy dies, they explode in a really cheesy way, and headshots are zoomed into every 5 minutes. That's fine but when it happens every single time, it becomes tacked on and just one little thing desperately begging you to pay attention to the game.
TRUE STORY: When I first heard and saw this game, I thought it was a PS2 game from Japan that was made a few years ago remastered in HD. Then I figured out it was built just for the PS3 and 360. To put it bluntly: the game is ugly in every way. Animations are like something out of a claymation movie from the 50's and textures look like they were rendered out of the N64.
There is multiplayer, but "surprisingly", no one was playing it so I didn't even bother.
All in all, nothing you haven't seen before, and if you have, it's already been done better anyway. If you spend $60 or even $5 on this title, you should be back-handed. It would be a nice prank to give it to someone, but then it hurts both of you in the end. Although Quantum Theory is innovative in original in one aspect: it asks where plagiarism stands in game development.