Darren Carver-Balsiger’s review published on Letterboxd:
I seriously do not recommend reading this review without having seen the film. That said, there's no explicit plot spoilers (just strong hints).
For most films I'm able to write a review, even if it's just a few lines, pretty much straight after watching. I generally wait, let it digest a bit first, but with Hereditary I had no choice. I could not have written about it straight away, even if I tried just to bullet point my thoughts. It was all pretty clear, I was planning to write about how it's a decent film but not the horror masterpiece everyone seems to be making it out to be. Then the ending happened and suddenly I see what people were on about. Don't get me wrong, it's still flawed and far from a masterpiece, but that ending is bound to be catnip for certain cinephiles and something many will adore. I've always said that a good ending can save any movie and the final scene of Hereditary wraps it up beautifully and made me increase my rating.
But ending aside, Hereditary is just mediocre. It has no identity of its own, just copying ideas all over the place from other artsy horror movies. It feels like a mix of Don't Look Now (seances, grief), The Exorcist (possession, mother-child relationships), and Kill List (that ending!!). Also, unlike the complex endings of Don't Look Now and Kill List, Hereditary actually boils down to something pretty simple and doesn't really feed into an overarching metaphor for its characters. My biggest gripe with Hereditary however is a very silly moment in the first act which kicks the rest of the plot off and requires a series of silly contrivances and ideas to get there. It's just too goofy but it's played so seriously. That doesn't mean Hereditary is bad, quite the contrary in fact, it's very good. It's just flawed in places. The atmosphere is effectively creepy and I admired the acting. It was messily decent, and then the ending made it really good. I'm alternating in my mind whether Hereditary is a great film with flaws or an okay film with real highlights, but right now I'm tending towards the latter.