John F. Beach's audition scene was the one where his character comes out of the bathroom dazed after having just witnessed one of the girls insert a lipstick into her breast.
Linnea Quigley, who played Suzanne in the Night of the Demons (1988), makes a short appearance in an early scene, wearing the same ballerina costume and shot from the same angle as she was in her first scene in the original film.
When in the room with the symbols Maddie begins to tell the story of what happened and that leads to what is happened at the point in time, when she starts the story it is night time but when she finishes the story it is day time but she continues to talk about the story and says that they will have to wait until dawn to escape the room when it is clearly already day time.
The amount of blood on Maddie's white shirt goes from a lot in the safe room, to hardly any when they leave it, to a lot again when she goes back into the safe room.