DirkH’s review published on Letterboxd:
Does exactly what is says on the tin. And for about half the time it does it really well.
The opening act is absolutely superb. There is an immediate sense of claustrophobic dred, shot with confidence and keen pacing. So I was really in to it, even finding Stewart's performance growing on me (I'm not a fan).
Ironically, the trouble starts when the monsters are introduced. This is a monster movie, so it was bound to happen, but director Eubank loses grip of his film. It's weird actually. He seems to understand the basics of evoking tension, but he foregoes everything and falls back on all the tricks unbelievably annoying and present in just about every dime a dozen horror movie. Jump scares, shaky cam and a lot of non functional darkness. The second act betrays Eubank's limitations, which is confounding when set against the first act.
In the final act, which holds no surprises, he reels it back in a bit, but that's a personal thing. I absolutely loved the creature design. Anyone who loves Lovecraft and Cthulu will get a kick out of it, trust me.
So this is a mixed bag, but certainly not a bad way to spend some time. And if you've got better things to do just skip the bits in the middle.