The chasm between digital life and meatspace may be the only truly new subject cinema has had over the last 20 years. Of all the current angles on it, Ramin Niami’s bric-a-brac assemblage of webcam thriller, sitcom and slasher film is certainly one of the more original – even if it doesn’t finally hold together.

Dakota Shapiro plays Henry, an improbably handsome voyeur and shut-in who has barricaded himself into a room in the Los Angeles apartment he has inherited, and spends his time watching women on a set of webcams he has hacked. There’s musician Sky, webcam girl Tess, new immigrant Linnea … and Henry talks at them all as if they’re old friends, when he’s not nervously wolfing downers in response to anything that upsets him. Then, in one scrying session, he sees Laura (Vlada Verevko), a piercing-eyed beauty with a scary boyfriend turnover, drag what seems to be a bodybag across her floor.

Drawn into Henry’s growing paranoia that he may have hacked a serial killer is his flatmate Eric (Luke Cook), a brash Aussie wannabe actor. Like in a classic sitcom, he is constantly bowling into Henry’s room to shoot the breeze, moan about auditions, and give girl advice to the loner. It’s as though Niami is saying these pithy and entertaining exchanges are what is important; real life in all its annoying, lively inconvenience, not the endlessly receding desires we pursue through a screen.

Played with excellent relatability by Shapiro and Cook, these bits are easily the most successful part of the film. More so than its last-act swerve into blatant genre mayhem, spun out of a hitherto unsatisfying chunk of Henry’s backstory. Even if the carnage steamrollers the first part’s amiably bleary digital-age comedy, Eyes Without a Face is still a fine showcase for the two leads. Cook is irresistibly crass and confident; the elven-featured Shapiro, who looks like a young Jude Law, surely has a new-generation Marvel superhero with his name on it.

• Eye Without a Face is released on 23 August on digital platforms.