Alien Hunter aka Welcome to Willits
I don't know why this film has the two completely different titles. It was "Alien Hunter" on my box, but Wikipedia has it under the "Welcome to Willits" title, which is probably more accurate, but less likely to sell copies.
Wikipedia describes it as a "science fiction horror comedy film", but I'm not sure where the comedy was (and very black if there was any), and there was really little science fiction either, it's pretty much a horror film, with a little bit of action film.
One review on IMDB (where it's under "Alien Hunter (2016)") says "wry, intellectual humor and wit", which I damned if I saw. Maybe you have to be from the USA or North California (where it's apparently set) to understand that element.
As slightly gory horror films go, it's fairly well done, and does take an original approach, but I can't say I'm overly impressed with it. I was actually trying to buy a different film, but this eBay seller was clearly too stupid to tell the difference between utterly different covers. Never spend much on buying films from small sellers on eBay, there are way too many idiots out there!
The large image of Dolph Lundgren on the cover is very misleading, as is the flying saucer. Dolph and any aliens only appear in the psychosis (probably) of one of the main characters. It's never entirely clear if he is actually seeing aliens, or whether it's entirely in his head, but I think it's likely the latter, so as a study of how hallucinogenic drugs could cause a redneck to utterly lose contact with reality, and psychotically rationalise reasons to kill anyone he met, it's not the worst example. Weirdly, quite a few reviews love it, and the remainder dislike it. I think some elements must really resonate with some people, so that they think it's wonderful, but I can't say I saw any of that. The film is mostly well enough made for a relatively low budget film, but the pacing is odd, and the acting mediocre.
If you spend a couple of quid on it, you'll probably get your money's worth, but I wouldn't go out of my way to watch it!