Connor Swenson’s review published on Letterboxd:
About as intense as you can get. Being trapped in this particular setting alone is great for some freakiness, what with all the claustrophobic moments, the intense quietness and a few natural-feeling jumpscares. Light is also used really well, both in terms of limiting it and using flares to cover the place in some cool, unnatural lighting. Of course the setting being good for horror just makes it all the better for when the real horrors starts.
If I had to complain I'd say that the characters are a little flat; they're not an assortment of stereotypes like other horrors, but at the same time I'd have liked it if their personalities were just a little more distinct. And as much as I like the lighting, it does not make for a very easily understood fight scene when things get more off the wall. Some might say the confusion it causes could add to the scariness, but all it did for me was make me kinda note how lackluster some of the effects are. Nothing terrible, but just the odd off one here and there.
I honestly think I prefer the movie before they show up, but it's only a marginal downgrade. Very intense and a hell of a ride, especially if it's the version with the good ending. Good as in quality. Very bad for Sarah.