Randal Silvey’s review published on Letterboxd:
A prequel set in the 70s which casts Sadako as the lead. This has been & continues to be my favorite of the franchise. It's underrated, imo, but I understand why it might be a miss for many viewers. It's a slow burn with very few scares. It's more concerned with channeling the quiet, eerie vibe of 1970s horror and telling a Carrie-esqe tragedy. For me, it absolutely nails that vibe, from the sound design to the camera work to the way it constructs its creepiest moments.
It attempts to paint Sadako as a sympathetic main character, which is a must if the viewer is going to be emotionally invested in where the plot goes. It works for me. Sadako is portrayed as slightly alien but mostly uneasy, vulnerable, and damaged. Understandably, that's a hard sell for some viewers.
Each of the Ring sequels I've watched this past week has added some weird, wild concepts to the overall Sadako mythos. The prequel adds one. I won't spoil it, but it could be a make-or-break twist for some. It took me a few viewings before I really warmed up to the idea, but I feel it's an appropriately creepy concept. It's not nearly as wild as many of the concepts proposed in The Spiral. Furthermore, it works to aid in the hard sell of making the horrifying antagonist of the last several films a truly sympathetic character.
In short, I love this film. It's almost horror movie comfort viewing for me. It's a recommendation if the phrase "slow burn" doesn't scare you off of a film. Don't expect big scares, either. It's all about the vibes.