I think FNAF was designed so that it would be horror, but also fine for kids to play. The first time I ever saw a video of it, I saw a toy chick scream with a cartooney sound randomly popping up on the screen. It was a jumpscare, but immediately after I saw what it was I began laughing my head off. I think it proves that one of the most scary things in horror games is the jump scare. Honestly, take out jump scares and they're not very scary, just creepy, gory, and many times disturbing.