I didn't, but I can now!
So this movie starts with some philosophical ramblings, as any good monster movie is wont to do. In voiceover, Kristen Stewart tells us that when you're so far underwater, time starts to act funny. Now, I love this shit. I was preparing for some Sunshine-y goodness with that line. The rest of the film abandons it, sadly, and basically just does the last act of Sunshine (which I love, but only because it was preceded by the prior two acts of space-y philosophizing). It's pretty much all action from the end of her monologue on, as the deep water drill gets compromised and the few remaining crew members must travel to other sites on the seafloor to be rescued.
That'd be a fine enough premise on its own, but here there be monsters, and it turns into kind of a greatest hits of the Alien franchise. If you're gonna build a monster movie, heavily referencing the Alien films (up through Resurrection!) isn't a bad way to do it. Those bones are solid, and Stewart can ably inhabit a Ripley-esqe role right down to her absurdly skimpy underwear in some precarious situations. The rest of the cast is fine enough, but nothing to write home about.
The underwater monsters are pretty cool, if a bit too anthropomorphic for my liking. They're basically long thin human-shaped things. That is, until the ending, which reveals a giant Cthulhu-type monster that looks really cool. Unfortunately, all it does is look cool. Stewart dispatches it with ease and then there's a series of newspaper headlines indicating a coverup by the corporation, a bookend to the opening titles which might suggest a larger plot going on here but the movie does almost nothing with that. In all, it's a movie that looks cool and is thrilling in moments, with a good performance from KStew and not a whole ton else going on in its head.