Great film for "what it is". A grimy and gritty realistic depiction of the dark and the light side of human beings, when placed in peril.
You don't need sky scraper high tidal waves or asteroids crashing in to Earth to create a disaster movie. If you want a film like that there is one released every year.
This film is just a tale of one man and his son trying to survive a long trek to the coast to get away from the despair of inland, with the faint hope there will be some form of a better life.
Performances are superb and there are some tear jerking scenes.
What really pleased me about this film is that it did the book justice.
Be warned... it is grim, it is slow, but it is probably how it would be if the world did end.