The film borrows heavily from other works—it feels like "The Babadook," but told through a mobile phone’s perspective—though the performances are generally good, and the monster designs aren't terrible. There are some effectively unsettling moments created by utilizing the device’s camera functions. I don’t know the reasoning behind casting an autistic pre-teen as Oliver, however Azhy Robertson delivers a convincing portrayal. It seems like I am not alone in being weary of the recurring plot element involving “school yard bullies picking on the young protagonist.” During the film's final act, one particular sequence managed to genuinely surprise me, which is saying something given how much I’ve seen. That unexpected moment made me reconsider my initial impression and ultimately led me to enjoy the movie more.

Source on TMDB