I'll endeavour to keep this review free of specific spoilers, but my 4-star rating is contingent upon me discussing various aspects of the film that are 'spoiler-adjacent'.
Tl;dr: the film retells the original FNAF 1-3 story and it's themes in a new, interesting way. The film takes the opportunity to establish its own canon and plays with the roles, relationships, and motivations of characters in a way which will be enjoyed greatly if it was something you expected, but will very well leaving you feeling like something is 'missing' if you were expecting otherwise.
From the outset, you can tell the love of Freddy's that was put into this movie's design. The animatronics are almost perfect, and if you view them from the visual perspective of a child, they *are* perfect. They have been lovingly recreated, and the puppeteers and designers deserve full praise. Likewise, the pizzeria's set feels completely familiar, and a brilliant job was done to recreate the atmosphere of the FNAF setting
Where the controversy with this film lies is, ultimately, in it's tone and the story. What we see here is a return to the more supernatural elements of FNAF, and a deviation from the more explict sci-fi direction the games started with Sister Location, and jumped fully into from Help Wanted onwards. I'm a huge fan of this; I had a smile on my face the whole movie, and am excited about this continuity in a way I simply haven't been about post-Ultimate Custom Night FNaF. Importantly, however, I expected the movie to be establishing it's own canon ahead of time, and as part of that I was fully invested in and awaiting plot details from the games to be completely changed.
I want to keep this free of spoilers, but if you forget everything you know about FNAF lore outside of *what was confirmed and speculated at the time of FNAF 3's release, and explicitly present within the games at that point*, you will feel much more as I did whilst watching the film and much less like something was missing. Changes to characters and their roles within the story will not feel like a let down, but rather a chance to explore the familiar story of those specific games with different players and perspectives. *That* is why I really enjoyed this movie, as it has taken the core story of the missing children which I already know, and presented it me in a fresh way that allows interesting dynamics between spirits, antagonists, and protagonists to be presented.
Tonal expectations are important too. This is a ghost story, which conjures up expectations of Ringลซ, The Grudge, or Exorcist. There is room for that within FNAF, and I hope to see it one day, but go in expecting scares and you will be dissapointed. Love it as I do, FNAF has still always been 'baby's first horror'. There's lots to find disturbing, scary, and unsettling within the established games' lore, but this movie was always going to have to cater to long-time fans, kids who were the same age as us when we first started exploring the series, and the parents of those kids. The movie isn't scary, but since I haven't been scared by FNAF since FNAF 4, I can't really complain about that. A last note on tone, one particular choice about the dynamics the animatronics play is something that made sense to me (given that they are *children*) and enables them to have a range of interactions throughout the film. I also think that the reason why this role changes is also adequately addressed (and is very much believeable from a game canon perspective, actually) but I can understand this one being harder to stomach tonally