Leesah Sea’s review published on Letterboxd:
It seems like a lot of people are writing off HORSE GIRL because it's "weird". This actually feels quite appropriate as Sarah (Alison Brie) descends into madness via hallucinations, vivid dreams, and paranoia. Brie gives a wonderful performance throughout the entire movie. She's carrying a lot here and she does it so well displaying incredible range.
My main issue with the movie is the ending. The final minute could have been cut and I would have been left enjoying this a lot more. It's funny how an ending can completely change your final thoughts on a movie.