Very poorly written...
This movie suffers horribly from clique Hollywood writing. The plot is driven in a very forced way. Throughout the movie, we see irrational characters making irrational decisions, and taking unnecessary risks. You know a movie is weak, when it relies on stupidity to make things happen. This movie is extremely guilty of that.
Also, someone said this movie adds nothing to the genre. I couldn't agree more. It's actually inferior to most movies in the genre. It's just a lazy, uninspired movie, and the writers/directors only have themselves to blame.