Lack of good storyline.

The film never slows down or bores, plunging from one harrowing sequence to the next.

I didn’t really have many expectations going into the movie (good or bad), but I actually really enjoyed it. I really liked the characters and the banter between them.

While it is a pity that the story wasn't told with more visual finesse, this is trivial compared to our real-world problems. It takes a good movie to put that into perspective.