There’s a familiar meta-narrative around horror films that rears its head a couple times a year nowadays. Phrases like “elevated horror” or “not really a horror movie” get thrown around by marketing teams, directors and even critics. While I’m open to interrogating genre boundaries – for example, I have a lot of time for “Why <insert-non-horror-film-here> is really a horror movie!” arguments – this particular rhetoric is at once specious and ahistorical. The underlying reasoning is clear; people aren’t going to flock to the theatre for a run-of-the-mill horror flick. But the implications are also unmistakable: a suggestion that the horror genre is entirely defined by lowest-common-denominator, formulaic films that are barely distinguishable from one another.

Hereditary is, unmistakably, a horror film. With a story deeply indebted to maternal horror from Rosemary’s Baby to, more recently, The Babadook, it features plenty of familiar horror tropes: things going bump in the night, satanic rituals, ghosts. The whole kit and kaboodle. While I won’t brook any superior attempts to separate it from its horror peers, it is important to acknowledge that Hereditary’s style – specifically, its rhythm – is distinct from similar films. This is an impressive if imperfect debut from writer/director Ari Aster, anchored by unconventional editing from Lucian Johnson and Jennifer Lame, along with an incredible, awards-worthy performance from Toni Collette.

After an obituary notice, Hereditary begins with a slow, silent observation of a room. The room belongs to the Graham family: parents Steve (Gabriel Byrne) and Annie (Collette), children Peter (Alex Wolff) and Charlie (Milly Shapiro). Within this room is a miniaturised model of the Graham house; a creation of Annie, who we will soon learn is an acclaimed artist known for her meticulous scale models. Gradually the camera settles on this model, pushing in towards Charlie’s bedroom. With sublime elegance, the model transforms into the real room, and our story begins.

This opening scene is more than a bit of showmanship. What Aster is doing is signalling the tone of the film. Where most horror films tend to rely on subjective immediacy, Aster and cinematographer Pawel Pogorelski make a conscious effort to keep us at a distance. While I can’t speak to the technical lensing going on here, that sense of miniaturisation is maintained throughout. We feel as though we’re peering in on these people, like a child over a dollhouse, rather than standing alongside them. Like many horror films, it corrupts the familial safety of domesticity, but it inverts the traditional perspective.

The film’s structure reinforces this sense of distance. While I feel that jump scares are unfairly maligned by fans and critics, it’s true that most horror films rely on surprising their audience to one degree or another. Hereditary is different. Aster uses foreshadowing frequently and heavily, signalling – rather unsubtly, most of the time – the suffering about to be inflicted on the Graham family. This is not a film that creates tension by waiting for something unexpected to happen. Rather, Hereditary gravely informs us that we are about to be audience to intimate suffering, creating tension through anticipation rather than uncertainty. The off-putting editing – with cuts never quite occurring where you’d expect – creates an unsettling rhythm that contributes to an overarching sense of wrongness.

Fundamentally, Hereditary is a film about suffering. It’s an uncomfortable film to watch, more disturbing than intensely frightening. That’s as much thanks to Collette’s committed, high-key performance as it is Aster’s direction. Collette vividly creates a woman resonating with pain, wracked with so much grief and guilt that she can barely stand to inhabit her own skin. Her work here is so intense that it could’ve toppled over into camp so easily, but instead quavers at an agonising frequency throughout.

It’s not until the third act – in which Collette is barely represented – that the film loses its carefully-crafted tone. When Hereditary explodes into the full-bore horror theatrics presaged throughout, it slips into familiar horror rhythms …and reads as ridiculous rather than terrifying. Perhaps this suggests that Aster is simply less confident with more conventional genre grammar, but I tend to think that it’s better explained by the disparity in tone between the film’s first 100 minutes and its final fifteen. Hereditary creates such oppressive tension then when it releases, it’s more funny than scary; my cinema was filled with laughter for much of the final act, which I can’t imagine was the intent.

While Hereditary doesn’t quick stick the landing, it is an auspicious debut for its director, demonstrative of a confident and unconventional take on familiar horror material – and boasting the best acting of the year, besides. Just don’t pretend it’s not a horror movie.