The filmmakers have obviously seen these types of monster movies in the past but there was one thing that annoyed them about those movies. What is that one thing? The first 30 minutes of “unnecessary” back story. I mean, most of the people are going to die anyway so why waste so much time on getting to know these characters? There are only 6 characters in this movie and you learn what you need to know about them while on the run to anticipated safety which allows the filmmakers to focus on the scenario at hand.
The movie hits the ground running in a way that is jarring and I think that is intentional. The filmmakers know the movie they are making and they do not apologize for it. The world-building is subtle and not in your face. The movie presents everything that you need to know onscreen and does not waste time over-explaining things.
The plot is simple and executed in a way that is very entertaining. A group of individuals at an underwater research facility are running for their lives from an unseen assailant to the only remaining escape pods left. That’s it. That is the entire movie. The tension and claustrophobia of this movie though keep you on the edge of your seat and so focused on what is happening at the moment that adding in additional complexity or sub-plots would have ruined the ride.
I definitely recommend watching this movie, especially in the dark with a decent surround sound to get the best impact.