Though it pays “creative homage” to a number of films (the opening credits sequence is practically lifted from the 2014 version of Godzilla ), it owes its biggest debts to Alien , Aliens , and the collected works of Paul W.S. Anderson, the sci-fi deathtrap B-movie maestro behind Event Horizon and the Resident Evil films .
There’s no doubt that Kristen Stewart has been styled to evoke Weaver as Ripley in Underwater , to the point of collapsing the character’s various incarnations into one package: She’s got close-cropped hair (shades of Alien 3 ), carries a big gun (á la Aliens ), and spends a significant amount of time running around in her underwear (as in the climax of Alien ), all while projecting the same terse toughness as her inspiration.
There’s a scene where the crew is crawling through a tight space in the lab wreckage that evokes the claustrophobic panic of The Descent , and the slow reveal of the final water monster baddie is spookily reminiscent of the Queen reveal in Aliens .
In addition, the alien design borrows from earlier films like Alien (from which director William Eubank has also cribbed the interiors), Aliens and A Quiet Place , to name just three.
Similarly, the sense of claustrophobia director William Eubank accomplishes in early sequences is neatly taut, and several of the reveals of the underwater monsters are quite eerie and, wouldn’t you know it, reminiscent of the Queen from the superior Aliens .
There's a wise-cracking crew member, played by T.J. Miller, who's clearly a descendant of the whiny marine played by Bill Paxton ( "Game over, man!" ) in Aliens .