David (Haley Joel Osment) is a robot designed to look like a young boy, and is the first of his kind designed to feel real love. He’s assigned to a couple (Frances O’Connor, Sam Robards) whose biological son Martin (Jake Thomas) is in a coma, but when Martin returns they abandon David, who goes on a quest to become a real live boy.

Developed by Stanley Kubrick before his death and completed by Steven Spielberg, A.I. is a Spielberg movie through and through, but with streaks of Kubrickian influence, from the buildings shaped like erotically-posed women to the twisted steampunk flesh fair, where religious fanatics torture robots for entertainment. This sharp edge surrounds a sentimental tale of a child finding his way back to his mommy in what sounds like a robo-nightmare on paper but is actually one of the most poignant and moving sci-fi films ever made.

David is accompanied by pleasurebot Gigolo Joe (Jude Law) – surely another Kubrick idea – who’s designed to fulfill women’s emotional needs in a very different way. In fact it’s easier to see how Joe can meet women’s sexual needs than a robot which never grows can fulfill the desire to nurture a child. But this can be excused as it’s one of the few films to look at our obligations to our creations, rather than the threat of AI.

As such the focus is entirely on the robot characters. The opening narration establishes a dystopian future where mass human extinction has left a tiny number of spoiled rich people who have every material need catered for by their mechanical servants. Enter David’s parents who constantly make incomprehensible, irrational choices, perhaps caused by their inability to deal with emotionally challenging situations due to their insulated existence.

The fixation on its metallic main characters is made manageable by an incredible performance from Osment, who shows a remarkable degree of self control and an emotional maturity far beyond his years. The visual effects are some of the best-used ever, combining animatronics, makeup and CGI to create all manner of robotic effects with seamless results that still look brilliant 20 years later. It also has a sublime John Williams score.

It’s not perfect – it often over-explains the plot and its central moral debate, and the ending won’t suit everyone (although personally I like it). It’s also rather heavy-handed on the literary metaphors. But by combining the natural intelligence of two cinematic masters it creates an entirely unique and engrossing film which has aged as well as a robot frozen in ice.