Philip Carroll’s review published on Letterboxd:
Right from the beginning, this movie had a sense of dread and uneasiness to it. That's when I knew this was going to be a great/true horror film. I don't think there are many true horror films today. Most of the so-called scary movies rely on cheap jump scares rather than having a real sense of horror that will stick with you long after the movie is over. I know I've said it before but we need more horror movies like these.
A widow struggles with her troublesome child and his fear of a monster in the house. One day she finds a strange book in his room about a monster named the Babadook that terrorizes people in a house once they let him in. Sure enough, she begins seeing this monster herself.
I realize it may sound similar to "Evil Dead" with the main character reading a book that releases evil on them but it couldn't be farther from that. The movie is really about a relationship between a mother and son that are expertly crafted into a horror story. They really could have gone with any genre for this story but the fact that they chose horror made this feel so fresh and new.
I don't want to give too much away but I will say that I found the ending to be very original and satisfying. Though, it may not work for everyone. But that's just the risk you take with horror movies.