An excellent fan game. It embraces what makes FNAF unique and interesting while putting a unique mechanical and thematic spin on it. The main levels all do a great job of gradually introducing new mechanics and ramping up the difficulty, and the challenges help keep the game interesting even after you've beaten the main game. I truly appreciate the introduction of new mechanics in the challenge mode instead of just shuffling the characters and their difficulties around. It amazes me that such a level of polish can be devoted to a fan game. It speaks to the creators' love of the franchise.