It's NOT "The Superdeep", but it's similar. There's a plant based life form killing people underground in a mining or military facility. The production is very dark and gritty, seemed fairly low budget. I think the language is Russian. I watched it around 2016 I think, and it was made in the 2000s.
1 Answer
This sounds like EDEN LOG (2007).
Wikipedia summary:
A man wakes up disoriented, deep inside a cave. Suffering amnesia, he has no recollection of who he is, or how he got there. A dead man lies next to him. As he stumbles around in the limited light, he comes upon a dilapidated area with damaged pieces of technology all around him. A registration plays, explaining the place is a sort of processing network called Eden Log, whose workers are all immigrants promised citizenship in the society above ground. The workers are apparently harvesting the sap of a gigantic plant whose roots and vines are now everywhere in the underground complex, which appears abandoned.
