The first two thirds are good, but the ending is unrewarding.

Rating: 7/10 (25 March 2016)

Good suspense/ thriller about a girl injured in an accident, blacking out, and waking up chained to a wall in a cement cell, just ever so slightly out of reach of her cell phone and personal affects, similar to the original Saw. Her cell keeper is revealed to be Howard (another good turn from John Goodman) who warns her she is in a bomb shelter following a chemical warfare attack, and is being held there until it's safe to go above ground.
Much of the film is the two of them, and one more "survivor", trying to make the most of this bizarre situation, and figure whether his paranoid ramblings are valid.
Is Howard telling the truth, has humanity perished? If they have, who is responsible, and when will they be able to leave?
Another twist paints Howard to be a delusional killer, which is never followed through with, or built upon.
Alien invasion appears in the final reel, making me wonder would that make sense, and the three separate plot lines might tie together if I had seen the original film? As it is, this tense and occasionally creepy thriller feels more like three plot lines twirled together, without a satisfying ending to them, just a setup for more films. This is the second film I have seen this week that I can say that about.
Being watered down to a PG13/rating probably didn't help, either, as it somewhat limited the on-screen violence in a couple of scenes.