Utterly Mad

Gameplay wise there really has been no improvement through out the FNAF series, just making it more difficult by taking away doors and occasionally have your cameras turn off. Story wise I think it could rather easily make an R rated horror movie(child murder...not going to get pg 13).

Though yeah from everything I've heard HP Lovecraft's work would make the better movie.
Also, look up The Bunnyman Massacre... like wtf...