Simple and well acted, it has tension enough to knot the stomach.

Fun premise, good actors, bad writing. This film seemed to have potential at the beginning but it quickly devolves into a trite action film. Ultimately it's very boring.

While it doesn't offer any answers, it both thrills and makes you think.

It's the kind of movie you'll want to see a second time with someone who hasn't seen it yet, to remember what it was like to watch it for the first time.