Backrooms had a lot of material to work with. The concept's original 4chan post evoked unease right off the bat, with turns of phrase like "the madness of mono-yellow" and "something wandering" piquing both curiosity and a pinch of nerves. Subsequent wiki installments played on the "six hundred million square miles of randomly segmented empty rooms" (three times the surface of the Earth!) to craft an eery yet broadly consistent world. And most relevantly, Backrooms director Kane Parsons, then only a teenager, crafted a full web series grappling with the physics, philosophy, and themes of the unnerving parallel world. 

All of that creates a robust and believable world into which this year's movie adaption can plunge, and the sickly carpeting and warped furniture of the liminal space certainly gives audiences ample heebie-jeebies. But the feature-length story, written by TV veteran Will Soodik and led on-screen by Chiwetel Ejiofor and Hollywood darling Renate Reinsve (hot off her fantastic turn in Sentimental Value), ultimately falls into more traditional mental-health-horror tropes while stripping away some of the worst possibilities of the Backrooms levels. 

That mitigation — the narrative devices that offer some sense-making to the Backrooms and therefore pull away its inhuman and irrational fear — starts from the first scene, in which scientists are seen watching found footage of an explorer being killed in the liminal space. The sequence is otherwise terrifying, with a heart-pounding POV lens and grainy and uneven views of the miserable yellow hallways, but the scientists' presence almost rationalizes it too quickly. 

Nevertheless, we soon meet Clark (Ejiofor), an alcoholic divorcee who runs a crappy architecture store after failing at his primary dream of becoming an architect. He's being counseled by psychiatrist Mary (Reinsve), whose own traumatizing childhood has helped her therapize and support others. Clark is maddened by electrical malfunctions in his store, and in searching for their cause passes through a wall in the store's basement into the Backrooms. His architectural mind is immediately taken by their infinitude and complexity, and despite some near brushes with creepy sounds and threatening footsteps, he quickly attaches new meaning to his discovery. 

After unsuccessfully trying to convince Mary the truthfulness of the space he's found, he recruits an employee and her boyfriend to join him in the Backrooms and film his expeditions. Tragedy and horror strike, though, and the three disappear. Haunted by her own failings, Mary kicks off a search for Clark and the two others. 

Most importantly, the movie is scary. That's certainly true in the Backrooms, from the nauseatingly tense opening sequence to Clark's doomed exploration mission to Mary's near-immediate discombobulation herself. Ejiofor sells his drunken egotism and descent into madness, while Reinsve is more sympathetic and confusing as the character we spend more time with by the end. Even Mark Duplass, whose role as one of the scientists is frustrating in its distraction from the main thrust of the film, pulls off one pregnant glance that signifies much darker forces at play. 

Monsters and inhabitants of the Backrooms are gross yet reflective of the space's haunted purpose. Physical set design, including 30,000 square feet of soundstages built by production designer Danny Vermette, makes us feel as lost as the characters as they stumble around the never-ending rooms. And for all their strangeness, the default yellow starts to feel somehow comfortable — allowing us to empathize with Clark and his appreciation for the Backrooms, but also making it scarier when the characters come across new Backrooms settings like a massive indoor skyscraper or a flooded pool. Even spaces outside the Backrooms, like parking lots, office buildings, and house parties, are imbued with a feeling of being non-places that sets us off. 

But for all its strengths and real uniqueness as a horror thriller made by the Gen-Z era (and its asexual mores, distrust of authoritiy, and increasing technopessmism), Backrooms is ultimately too content in an easy way out: mental health drama. Too much in all our main characters is chalked up to depression, addiction, and struggles with self-worth, and grand monologues overexplain decisions that needed no explanation in the first place. Sometimes this allows Ejiofor and Reinsve to bust out their acting chops, such as in two memorable role-playing exercises, but mostly it shelves Backrooms too neatly in the 21st century practice of making most horror about mental health at the end of the day. 

Along with Obsession, it's thrilling that young new directors are doing more with less, especially in the tactile and ever-changing horror genre; I just wish more of them went Baker's route of making things scary without resting weightily on Parsons' crutches.