Do yourself a favor, good reader. When the bulk of reviewers on this site advise you not to waste your time on a particular film, do listen.
Unfortunately, I did not heed the warnings offered by other contributors here, and I wasted about an hour and a half on this piece of dreck. My time would have been better spent clipping my toenails, and then trying to glue the clippings back into place.
I understand that horror is a difficult genre; essentially the same themes are recycled over and over, with a tweak here and there. There are, however, some films that should have never been made. "All Light Will End" is one of those. Far and away the best thing about this movie was the light comedic relief offered by the two featured deputies... and that ain't saying much.
Spare yourself. Do something else... ANYTHING else. Juggle chainsaws. Go swimming in the ocean with a bloody pork chop strung about your neck. Pick a fight with a nest of angry killer bees. Lay naked on a fire ant colony. None of those things are as potentially torturous as watching this movie. It really is that awful.