It gets under your skin...
This film is set in a dystopian, post-apocalyptic future. We know this because people dress in beige and sweat a lot. There’s a lot of sand, too, old houses, but very few establishing shots. The characters live in a version of the U.S. that has been taken over by an organization that has been spreading a deadly parasite in the population. Parasite is about this and a million other things.
The story is hard to keep up with because the budget is so low that the picture doesn’t convey the right mood. This film shouldn't have been made in such conditions. And what is a shiny black Lamborghini doing in the middle of a wasteland? Science-fiction is harder to afford than horror movies. This is an hybrid of the two genres. Its horrifying facet is more interesting than its scientific one.
The costumes aren’t convincing. The landscapes are almost inexistent. The sets are obviously improvised. In fact, everything, here, seems improvised. The creature effects are interesting but not memorable. This is a low-key version of much grander films. If what you want is a movie about parasites, then that’s what you get. At least, the title won’t mislead you!