The only FNAF game I've played is Pizzeria Simulator. While I haven't played any of the other games, I have a relative who has, so I've seen them play Sister Location, and I've seen game footage on Youtube. I also know the lore, and I wanted to prepare myself with this information, prior to watching the movie.
It was very, very well done. I also liked how the pacing of the movie went. With FNAF lore there is a lot to it. Obviously, you can't explain ALL of the lore in one, 2 hour movie, but what they showed was just about perfect.
I'm more used to a "out of 10" scale, so I give it a 9/10.