Disturbing in an unpleasant and lazy way

Much of the unease comes from the nasty music and color-inverted imagery. It feels a bit like cheating. The rest still holds plenty of shock value, but somehow it felt like that was the sole purpose instead of telling a story. Like Rob went 'Oh look how shocking this is", "Just look at this scene!"

This time, the mindbender is the movie itself

I am not sure how a 4th sequel could have worked or what I wanted from it, but surely it wasn't this. I hate the lazy self aware 'meta' approach and the revisiting of classic moments. Nothing really works anymore, I cringed multiple times. An odd misfire, which makes you wonder how this came to be.

Sweet little mystery

It could be said that the content is fairly minimal, but this didn't bother me at all. It is wonderfully mysterious, the slowness just adds to atmosphere and feeling of desolation, and they were really able to get the most out of the awe inspiring scenery and mystical abandoned town.

Adult enough to avoid horror pitfalls, but doesn't add much either

For the most part it stays away from cheap scares, and has enough confidence to slowly but surely built up the tension and story, and reach a fairly creative reveal. But it fails to get under your skin as it remains slightly tame and suffers from some implausibility.

Unable to cash in on the fantastic concept and visuals

This is an awesome idea and the underwater footage looks fantastic and bone chilling, and must have been tricky to film. It is almost incomprehensible that they still managed to make this NOT scary - but the banal horror story and robotic underwater conversations did the trick. A rewrite, please.