This is a full review of the Xbox 360 version of Quantum Theory. They call it "A diet version of Gears of War".
From the Review:
"It’s great to see Tecmo Koei, a Japanese company, attempt to break into third-person shooters, a largely Western dominated genre. While Quantum Theory is certainly a flawed experience, it offers a lot that separates it from Gears of War and other third-person shooters. I wouldn’t buy the game, but it’s certainly worth a rental, especially if you have a thing for third-person shooters."