Another instantly forgettable addition to the small horror/Sci-Fi niche of "send in the military cannon fodder" movies. What is that? You might be surprised just how many low-keyed movies there exist dealing with random military men (and women) being sent into a top-secret and geographically remote government research facility or underground lab to eliminate some sort of experiment that went horribly wrong. As a matter of course, these people haven't got a clue what they will be battling against and, regardless of their intense training and superior skills, they get mercilessly ripped to pieces by something (usually an alien or a genetic experiment) much stronger and slimier than them.
"Death Valley" is a new (2021) movie, but it doesn't bring any fresh or innovative elements to the already long overdue formula. Quite the contrary, the film features the same old clichés and dire stereotypes that were already introduced in the foundational landmarks of the genre; - like "Aliens", "Predator", and "Resident Evil". The noble soldier promising to his pregnant wife this will be his last mission, the jolly & joking brother-in-arms, the buffooned Russian mercenaries as opponents, the rescued scientist holding back a few dark secrets, etc. Etc. The plot twists, turns, and becomes unnecessarily complex towards the finale, but whatever. Nobody pays attention to the plot in films like these. I liked the monster, which looked to me like the illegitimate offspring between the Chattermouth cenobite from the original "Hellraiser" and the eyeless creature from "Pan's Labyrinth". Other than that, not much special.