While I haven’t seen his entire filmography, I can state that, in my experience, Steven Soderbergh doesn’t make bad films. His films are formally accomplished, sharply-written and modest in their ambitions. Unfortunately, he also seems to be unable to make a great film. (Though I’d have to rewatch Out of Sight to assert that with absolute confidence.)

Unsane is the latest example of a good-but-not-quite-great Soderbergh movie. It boasts the kind of lumpy, low-budget indie experimentation that defines his early works; if you’ve heard of the film, you probably already know that was shot on iPhone. The lo-fi aesthetic is unmissable through every wide-lensed frame; it looks cheap, and by Hollwood standards it certainly was: the $1.5 million budget must have primarily gone to its cast.

A psychological thriller which draws from – amongst others – Repulsion, Klute and Brian De Palma’s The Fury (whose then-teen star, Amy Irving, appears here as the protagonist’s mother), Unsane leans into the scuzzy aesthetic by tapping into that grimy ‘70s genre-flick feel. Rather than opting for pure, outsized genre thrills however, Soderbergh infuses the film with a twist of realism. The film feels halfway between a midnight movie and a Snapchat story, which perfectly suited to evoking a disorienting atmosphere.

The film begins following – literally, through voyeuristic camera angles – young professional Sawyer Valentini (Claire Foy). She’s clearly unravelling; she sees the face of her stalker (Joshua Leonard) on strangers and has a violent aversion midway through a Tinder hookup. When she checks into a counselling appointment at a mental health centre, she soon finds herself involuntarily committed – after some offhand comments about suicidal thoughts – to the institution, and the plot begins in earnest.

Any film in this vein is going to play with the inherent uncertainty of the cinematic image. Is Sawyer a sane if damaged individual exploited by a system designed to suck insurance dollars out of her, per fellow inmate Jacob (Jay Pharoah)? Or is everything we’re seeing a delusion concocted by an unwell mind? The later possibility seems likely early on, especially when Sawyer assaults a nurse after – briefly – seeing him wearing her stalker’s face. The overall effect is borderline nauseating, as we’re torn between sympathising with this woman and appraising her sanity (or lack thereof).

This uncertainty comes to a head when, on her second night in the centre, Sawyer runs into her stalker working in the facility handing out meds. The ambiguity of the scenario accelerates, like a balloon on the verge of popping. Either she’s legitimately unhinged – imagining innocent orderlies as her tormentor – or we’re in the kind of lurid thriller where ordinary logic is superceded by hyper-competent villains. It’s a disappointing revelation, to be quite honest; up until now, Soderbergh had done a superlative job of cultivating a realistically terrifying narrative – one that digs into how women are exploited and ignored and how health is secondary to profit – with the confines of what appeared to be a genre flick. Conceding that this is just another genre flick feels like a failure.

After this point, Unsane remains …well, I was going to say entertaining, but it still pretty nauseating, so let’s just go with competent. But any possibility of greatness has since sluiced away. There’s something inherently uncomfortable about the film’s nervous tightrope between serious social issues and genre schlockery though. I was reminded of The Girl on the Train. Granted, that was a vastly inferior film, but each draw in their audience with genre tropes before hitting them with very real trauma. That in of itself is fine, but neither evince much of an interest in examining the psychological or sociological foundations of that trauma beyond the basics. Neither establish a plot that stands up to any scrutiny; fine if you’re committed to the genre bit, not so much when you’re tugging at strings attached to abuse and gaslighting and worse.

Unsane could have been great. It could have been an unnerving but ultimately lightweight genre flick, content to thrill and surprise its audience. It could have been a rug-pull of a genre film that offers robust, thoughtful commentary on how mentally ill women are exploited and abused, and the machinations that drive that abuse. Instead, it balances in the precarious middle ground and comes across as another Soderbergh goof – a formally formidable riff that needed more time in the oven.