Overall it is a really interesting take on the end of the world. I wouldn't classify it as horror so much as a sci-fi drama with physiological tension. Well worth watching if you have Amazon Prime and it's free. Not sure I would pay extra money to rent it though.
Low budget and not much cast or special effects budget. Really more about what four strangers (and a baby) do when thrown together at the end of the world. For the most part it is really well done. Sound mixing, music, camera work, and acting (for the most part) is really good for a low budget movie. Pretty well written, though no full explanations are ever given on what is happening. Then again, how would these four people in a desolate cabin have anything more than theories about what is happening? So in that respect the script, though not fully satisfying, stays true to itself.
The one major low point of the movie is something many other comments mention, one actor and her character Heather is really not very believable. Not sure how much of it is an issue with how the character was written or how much is the actress' portrayal of Heather. She was clearly written to be antagonistic to the rest of the group, but it just didn't play out quite believably. Heather isn't a good person. We get it already! Does she really need to be argumentative and antagonistic the whole time? Even the worst people know how to play nice some of the time when it serves them. It would have been more believable if she pretended to be nice at least some of the time, then revealed herself to be truly horrible.
There are a few other things minor things that detract a bit from the movie. The beginning credits run a bit too long and the camera occasionally (for a second or two) is not focused quite correctly on the actor(s).
FYI: The trailer doesn't do justice to the sound mixing in the movie. I watched the trailer and could barely hear a thing over the music, but read the comments and noticed someone complimenting the movie on how clear and crisp the dialog could be heard. Watched a bit of the movie to check for myself and sure enough, the dialog is easy to hear over the background music and effects. It sucked me in though and what was supposed to be just checking if the movie was watchable ended up with my watching the whole movie.