The movie revolves around a classic alien abduction, "greys" with big black eyes, disc shaped saucer UFO's, levitation beams etc. The main character manages to kill one of the aliens and the hunt begins. The movie plays more with slow scare tactics rather than jump scares, gore or fight scenes. The main character spends the better time of the movies runtime of 90 minutes being scared and/or running. There is next to no voice lines in the entire movie, you will hear more heavy breathing than words. Actually, the aliens have more voice lines than all other characters combined, and their language consists of sound effects.
The endings is... Well, it's an ending at least and at no point did I feel that the movie was to short. It could have had a runtime of 60 minutes and told the same story.