It’s What’s Inside review – buzzy, big-sale Sundance thriller is a little empty

With this year’s festival entering its dying days, market news remains unusually slight, a surprise given how strike-impacted buyers were reportedly foaming for schedule-fillers. Big sales so far haven’t been all that big – Jesse Eisenberg comedy A Real Pain at Searchlight, Steven Soderbergh ghost story Presence at Neon – and so there are questions that still need answering going into the last weekend.

Related: Handling the Undead review – sad, slow-burn zombie drama is less gore, more grief

But earlier this week, as others umm-ed and ahh-ed, Netflix made a bullish statement with a $17m purchase of low-budget mind-bender It’s What’s Inside, an unusually high number for a genre film without any stars attached. While it may well be trumped over the next week or so given how other, more commercial titles remain unsold, it’s currently stamped with this year’s biggest-of-fest tag. That comes with a mostly terrible, tortured history, huge expectation leading to little reward, festival fever cured by lower altitude. Because for every Coda, there’s a Hamlet 2 or a Late Night or a Happy, Texas or a Birth of a Nation. The domination of streamers (forking out the most in recent years for films like Fair Play, Flora and Son, and Palm Springs) might have moved the goalposts for what success really means right now but buzz remains easier to measure and a talked-about hit in the mountains is too often a miss on the ground.

An easy guess with this one would be franchise potential, the kind of nifty conceit that could run on and on and Netflix has shown itself to be a streamer as obsessed with sequels as any studio. The details of the conceit are to be kept under wraps for now (whether Netflix can maintain such secrecy once a marketing campaign kicks into gear is to be seen) but it’s all about a suitcase. It’s brought to a remote country mansion by an estranged friend making a surprise appearance at a pre-wedding party, tensions packed in tight alongside. It contains a game he insists that they play, something they’ll never have seen before and something they must remain quiet about outside of the house. Chaos, and hysteria, follow.

What’s inside It’s What’s Inside is a bit of Talk to Me, a bit of Bodies Bodies Bodies, a bit of Ready or Not, a bit of Agatha Christie and a lot of attention-seeking trickery. The all-consuming maximalism of it – from intrusive score to obnoxious needle-drops to gimmicky cutaways to some top-of-the-lungs yelling – is dialled up so exhaustingly high that it’s hard to see a great number of Netflix viewers not clicking away during the opening, grating 20 minutes. The house itself – the product of a dated cliche: the brash, untalented pop artist – is exaggerated to the point of parody and the film is consistently hampered by a lack of atmosphere, something absolutely vital in a mysterious Christie setup. Greg Jardin’s obsession with garishly unreal multi-coloured mood lighting is a misfiring flourish and it all looks even shoddier when compared to the festival’s more beloved genre breakout I Saw the TV Glow, a film that uses an abundance of colour so gorgeously, it’s impossible to forget. The only thing evoked here is a plasticky film set.

It’s not just TV-trained first-timer Jardin’s film-making but his writing too, most characters drawn as lazy, one sentence cartoons – the vapid influencer, the sage-burning hippie, the white guy with a blaccent, etc. The jabs at social media are particularly clumsy, as if the script was written years ago and just recently dusted off, no changes made, and so while it all might have the bravado, and prodding insistence, that it is a “film of the moment”, it’s often strikingly uncool. Jardin demands a lot from his no-name cast, including The White Lotus’s Brittany O’Grady, and while they don’t all succeed – it’s a challenging acting exercise that many would fail – it’s at least a committed showcase.

When the artless swagger is tempered and Jardin allows the goofiness of his premise to fully take over, there are some fun, twisty stretches especially as the game gets deeper and nastier. Characters gaming out how to come out on top leads to some neat reversals but it also gets to be maddeningly convoluted, a slicker hand needed during a last act of fatiguing back and forths. We’re also being led towards something a little more ground-shifting than where we actually end up, a shoulder-shrug of a reveal that should have been a jaw-drop.

There’s a cracking elevator pitch of an idea here (one wonders if inevitable sequels will be able to squeeze more juice from it) but Jardin’s cocky, in-your-face excess coupled with his lack of follow-through makes this an unwinnable game.

• It’s What’s Inside screened at the Sundance film festival and is on Netflix from 4 October.