A third-rate Alien knockoff bolstered by surprisingly game on-screen talent and some decent atmospherics. The main issue here is a distinct lack of reason for being — Why are these characters and the barely-alluded-to corporation they work for drilling on this impossibly massive platform in the Mariana Trench? Why do the creatures look exceedingly terrestrial? Why does everyone have to strip to their skivvies to fit into their spac- I mean, *diving suits? Well, because the audience wants to see sparks fly as Kristen Stewart gets battered around by fleshy grotesques in her underwear.
Stewart does an admirable job embodying the Ripley-mold, but her character is paper-thin and leaves little to attach to. Unlike the crew in Alien or any number of recent lesser retreads (like 2017's Life), the supporting characters here lack anything more than a single, perfunctory background motive for even existing. Cassel, Athie, and, surprisingly enough, TJ Miller do what they can to breathe a little life into their poorly drawn roles, but they never feel like people because they're never given an adequate chance to flesh themselves out.
William Eubank's direction is similarly frustrating. His earlier work in 2012's The Signal was, at least visually, sensuous and intriguing, but here we see him recycle and often misuse the same tricks he used in that film, only with a much, much larger budget. Prepare yourselves for needless slow-down effects, too many mid/close ups, and largely unintelligible CGI set-pieces on the ocean-floor. To call the editing choppy would be an understatement, while admittedly pretty fitting; nearly every aspect of the film, from the action sequences to the story-telling at large, is hindered by what I can only assume was a slapdash effort to salvage a shipwreck of a production. You know you're in trouble when TJ Miller is the highlight of your movie...
On the plus side, Underwater features inspired (if completely unrealistic) set and costume design — I love the armored, space-esque industrial diving suits, in particular. The cinematography is generally fine outside the muddied action set-pieces, and the concept across the board holds a lot of potential, albeit potential that's been delivered far better in the decades prior to this release. Overall, though, Underwater is far too light to stay at the depths it aims for.