David Robert Mitchell is back with his first film in eight years, this time produced by JJ Abrams. It is initially amusing but oddly inert; contrived, derivative, commercially driven and weirdly inconsequential, a Spielbergian mashup about dinosaurs running amok in suburbia that doesn’t feel like homage so much as a pastiche produced by an AI Spielbergbot – except, I admit, for the moment we see two dinosaurs enjoy the full, physical flowering of romantic intimacy. That is not something Spielberg would feel comfortable showing – for dinosaurs nor, indeed, humans.

I was one of the frowning naysayers unconvinced by Mitchell’s madly indulgent LA fantasy-noir Under the Silver Lake, a giant disappointment compared with his breakthrough, the scary masterpiece It Follows. But at least Silver Lake had ambition and chutzpah. This feels as if Mitchell is going through the motions – someone else’s motions. We are in late-1980s small-town America; at one point, a character sits in a car listening to Steve Winwood’s Valerie. Ewan McGregor and Anne Hathaway are Greg and Denise Platt, an unhappy couple who live on Oak Street with their two kids, Brian (Christian Convery) and Audrey (Maisy Stella). Greg is ashamed of his failure as a breadwinner, having a humiliating side-job delivering pizzas. Denise is secretly writing an autobiographical novel about a woman planning to abandon her family.

At the height of their discontent, the family are perplexed by a sudden change in the atmosphere. It becomes unbearably hot and humid; a plant thought to have been extinct for millennia springs up in someone’s garden; a pile of mysterious ordure materialises in the mean neighbour’s yard. Then, we see glimpses of alien-looking scales and claws vanishing behind fences. It appears that a dinosaur-infested part of the prehistoric era has landed in the Platts’ neighbourhood – or that their part of modernity has been transported back to that time. The key to this mystery appears to be a glowing ball of light that vanishes and reappears in various locations. “Maybe this will take us home!” says Greg, presciently.

Are the dinosaurs symbolic of the family’s suppressed passions and concealed rage? Or is this the displaced seismic eruption that their domestic frustrations have been leading up to? Maybe – but these emotions feel less real than the dinosaurs. Either way, Mitchell can hardly resist shooting a shocking moment without cutting to a framed family photo showing a happier time. And he has a weakness for the eerie “split diopter” shot, much beloved of Brian De Palma, depicting a foregrounded face and background detail in the same dreamlike sharp focus. There’s a moment of fatal violence that is rather tamely cancelled out, and the element of jeopardy is missing. The End of Oak Street is fun at first, but it feels like Mitchell doesn’t really believe in any of it.

• The End of Oak Street is in UK cinemas from 14 August