A good psychological thriller

Rating: 8/10 (4 January 2019)

After reading so many deprecating reviews, I decided to watch the movie and judge for myself. I don't understand why people are giving it 1-4 stars.
It's a good movie. Definitely not the best out there, but it's thrilling enough to leave you craving for explanations. The plot is alright, the focus being not only on surviving under the ominous threat, but on the characters' psychological behavior.
I don't think it's a bad movie. It's at least average, compared with Hollywood blockbusters.