I've started to watch this and seen the first 2 episodes. Regarding it being classified YA. There is quite a lot of story based at the High School and the main character hunting for keys is a young boy. However, you have a strangling, and a great deal of gore shown (including in the making of The Splattering), teenage sex, adult sex and sexual language, and also a very great real sense of intimidation with menaces towards the child by the supernatural woman. It isn't something I would recommend showing to young children, especially if you want them to sleep. Young adults would probably find the child too young to be the centre of the story. Myself, I think I'm too old for everything, but this is trying to capture the same kind of Stranger Things audience.