This was a solid horror movie, very much not about the thing at the center of it--whatever beasts they may be--but much more about how humans would attempt to survive such a thing. It isn't a It Comes At Night sort of movie (literary horror movie where nothing much happens) but there is more heart to it than a standard horror movie where the characters are more or less cannon fodder for whatever hunts them. It's both well-filmed and acted. This was like the movie Signs was trying to be with some of the better elements of Don't Breathe (except without that extremely fucked up turkey baster part).
The background isn't so much important: creatures have arrived that are blind but apparently very good at hearing. You make a sound and that is enough to bring them (quickly) to hunt you--and there's no fighting them. One of the most interesting parts of this movie is the inclusion of a deaf character--the daughter. I'm very curious to hear what deaf people think of this movie. The family already knows how to sign because of her and there are some interesting shots that contrast how the other characters perceive the world vs her. (In some ways, she has an advantage: if she can't see it, it doesn't frighten her into making sounds, so she's safe as long as she's quiet.) One of the horror tropes I love is the "hiding from the beastie but you're terrified and have to keep from breathing too loud or screaming." There's a lot of that here, obviously.
While this is a great movie to see in a theater, it is NOT a great movie to see in a theater if people are talking, whispering, or crinkling wrappers. Like at all. It is largely a quiet movie--there's very little dialogue and long stretches without any loud sounds. (But when there are loud sounds, they are definitely loud.) I actually wish I could have seen this in a theater but with noise-cancelling headphones. (On the one hand, I don't want to be That Guy who shhhhs people, but on the other hand, STFU.)
Sidenote, whenever I watch something dystopian I can't help "but couldn't they have...?" In this case, placed a speaker in a quarry or large hole, surround it with explosives, turn the music on remotely, press play. Beasties run there, then get killed. Explosion sound draws other beasties who are killed by the secondary ring of explosives.
Anyhow, I definitely would recommend this movie--I'm frequently disappointed in horror movies because they're the same dumb thing over and over (Insidious, any knockoffs of Japanese horror movies--although I will say I have a soft spot for Paranormal Activity, even though it isn't actually good). I do think something new was brought to the table.