The Five Nights at Freddy's movie suffers from "criticpopcultureitis." Critics hate it because the extent of their knowledge of the game is their kid mentioning it once or twice or seeing a bonnie plush at a target. It's not the best horror movie ever made, but it's not supposed to be. In regards to a fnaf movie, I firmly believe it was the best it could have been.
Too close to the source material and it would have been a drag to watch after the first hour, but too far from it would result in a boring "out of touch" pop culture movie. Practical effects were phenomenal, 90% of the acting was great, and I just love Matthew Lillard. Fnaf fans will love this movie, and that's all we wanted in the first place, right? Hope they make a sequel.