I just watched it, and it was good imo. I played the game a couple years ago I think, and while the film felt indie in several places, I think they did a really good job with the budget and team they had.

The effects were pretty good (except some of the sub shaking scenes), the dialogue got a little mumbly, and they captured the feeling of the game. I'd say well done, and I'd like to see more people shoot for the moon with movies based on games. Hollywood sucks at it after all.