From the book introduction:
Shriek - The Game of Teen Horror is a simple-to-learn, cheesy roleplaying game where players take on the roles of disposable teeny-boppers in campy horror and slasher movies. It assumes the players and referee already have some rudimentary experience with roleplaying. It is meant to be played in the vein of Buffy the Vampire Slayer (the movie), Once Bitten, Scream, Friday the 13th, Halloween, and the like, so keep it light (yet terrifying).