Everyone has their opinion of Uwe. The man's made some horrible, horrible movies. But it seems like when he's working with his own material (i.e. not a video game) he can do some good work. Look no further than Postal (which, granted, is based on a game but is mostly original) to see that he is capable of doing good stuff that is criminally underrated just because he's Uwe Boll. I fear that may happen with Rampage as well.
The story itself isn't terribly in depth. It's basically just a frustrated young guy who's kind of a loser in the eyes of his small town who straps on a suit of full body armor, grabs some serious firepower, and mows down everyone he sees (mostly). I'd love to tell you that it's a serious look at the troubled mind of a small town guy who's pushed over the edge, but it's really not. It is, however, still quite good. Some people will probably get tired of a guy walking through town shooting random people, but I think it serves it's purpose to further the story and isn't completely mindless killing. What little story is there is pretty solid which is a hell of a lot more than you can say for a lot of Boll's work.
When all is said and done, I'd definitely recommend it.