The latest, most personal picture from Paolo Sorrentino, The Hand of God is a film of two uneven halves. Set in 1980s Naples and focused on Sorrentino’s alter ego, teenager Fabietto (Filippo Scotti), it is at first cacophonous and scattershot. With rumours circulating about Diego Maradona’s signing to SSC Napoli, there’s a fizzing excitement on the streets of the city. Fabietto’s extended family is boisterous, exaggerated, bursting out of the frame as regularly as his curvaceous Aunt Patrizia (Luisa Ranieri) spills out of her dress (spoiler: a lot). Toni Servillo and Teresa Saponangelo, as Fabietto’s parents, fill the story with love and laughter, mischief and marital drama.

And then, quite suddenly, they are gone. Fabietto is orphaned; it’s only thanks to his devotion to Maradona and Napoli that he escapes the same fate. And the tone of the film shifts to a more subdued and introspective second half. It feels like the sullen pall of smoke after a firework display. But then something changes. The writing and characters take on a more satisfying depth. Sure, the gaudy pyrotechnics of the early part of the film are fun, but it’s not until later that we start to know Fabietto as a person rather than a passive observer.

• In cinemas now and on Netflix from 15 December