Reviews imply that this is science fiction because there are aliens involved. This is a mild spoiler, but I get pissed by mis-classification like this: there's a drone shaped like a UFO, there are no aliens. Wikipedia classifies this as a "Weird Western," a genre I didn't even know existed - but it makes perfect sense given the proliferation of movies with Western-like structures and weird elements. This is a SPOILER (stop reading now etc., although this is a reveal that appears half way through the movie, not the ending): this is mostly just a Brazilian Western variant on "The Most Dangerous Game."
Bacurau is a small and isolated town in Brazil. We're introduced to the residents' lives, the local politics, details like how the drinkable water is trucked in, and the unusual characters who populate the place. Then weird things start happening (first the town disappears from Internet maps, then the phone signal drops) and people start dying (the movie gets pretty bloody).
I was significantly put out that this was neither as SF (in fact not at all) nor as "weird" as the reviews had implied. It's mildly unusual, a bit "weird," but many of the reviews at Rotten Tomatoes imply it's spectacularly unusual. In fact, on a scale of one to ten where Alejandro Jodorowsky is about a nine, this rates maybe a three, probably less. I wanted WEIRD, and I didn't get it. On the other hand, most of the people in the town are very well drawn characters: that at least was good. Overall - not really my thing.