Ryan Williams’s review published on Letterboxd:
A disappointment. Starts with a bang - a pretty brilliant opening act that culminates in as shocking a moment I've seen in a long time. From here until the halfway point, Hereditary is a viscerally uncomfortable examination of grief, guilt and the horrors of the family dynamic. Then, Toni Collette flips through one of her mom's books, finds some disturbing truths out and, just like that, all of the air lets out of the sails. The rest of the film's course is laid out and, well, you're either with it or you're not. For me, nothing in the film's familiar, tired final act could come close to topping the familial terror of the first hour or so.
If Aster can work out the kinks and better meld internal turmoil with external terror then I think he'll really have something. Here's hoping Hereditary is a signal post for better works to come and not a warning sign.