The PC port was a joke. In fact, the whole game was a joke. The multiplayer felt slow and clunky, and all maps looked the same. The graphics looked like Quake, and given that this game was bragging about being the first Call of Duty game on next generation consoles, that was an epic fail.
The campaign wasn't that short, and the settings were definitely unique, but I found it really lackluster, as if I was detached emotionally from the story. For example, when Riley got shot, I didn't become sad at all, in fact, given that I was playing on Veteran difficulty, I only complained about having to carry him.
I guess that the only redeeming factor of this game was the Extinction mode, which was mediocre at best, and the Snoop Dogg voice pack.