M O’s review published on Letterboxd:
Credit where it's due; this is definitely the best horror film of the past five years after THE WITCH and PERSONAL SHOPPER, and it's scarier than both. It also might be the most stressful two hours I've spent in a movie theater, with an outstanding cast led by a committed (career-best?) Toni Collette and budding Alex Wolff.
However, the brilliance of Aster's two-hour tension-building exercise is undone by a, I don't want to say cliched or stupid, but rather generic and anticlimactic ending. And when your whole film builds up to this one very straightforward, unambiguous point, that's a problem. It's especially a problem when the nihilism which preceded it is wholly unjustified.
To what end are we being put through the ringer? If the source of this artistic expression was cathartic and inspired by personal trauma, it'd be a much easier pill to swallow for the audience, but Aster explicitly stated at the TIFF Q&A that he simply set out to be a nefarious provocateur. When you're making a mindless B-movie slasher, that's cool. But when you tackle severe mental health issues and deep familial strife, the payoff's gotta deliver on an emotional, purposeful level.
HEREDITARY is one hell of a debut feature. I had just hoped it'd mean something, anything.