This movie is genuinely frightening. There's a good build up where you get to know the characters and they lull you into thinking it might not scare the pants off you and then... it scares the pants off you. It's not gory, just really scary and suspenseful. I almost cried for them during one scene where some of the main character are just so scared but have no way of exiting the situation and the actors are doing such a good job of expressing that hopeless kind of fear that we all dread, I really felt for them and was scared for them rather than being scared myself which was weirdly effective. I'd describe the emotional experience as terrifying, enraging (you'll see), and heartbreaking. I recommend it but you may not want to see it before bedtime. Have a comedy ready to cleanse your psyche.