When the Belgian animator Hergé died in 1983, he left behind one last, unfinished Tintin adventure. Entitled Tintin and Alph-Art, the story hinged on an evil scheme to abduct Tintin and encase him in liquid polyester. The gallant boy reporter would therefore become a "living sculpture", beautiful but dead. "Your corpse will be displayed in a museum," the villain (according to Hergé's notes) would cackle. "And no one will suspect that the work constitutes the last resting place of Tintin."
Three decades on, this dastardly plot may just have been completed. Out of the blocks comes The Adventures of Tintin, a rip-snorting Indiana Jones-style romp from director Steven Spielberg, darting from the cobbled streets of Paris to the bazaars and hill towns of north Africa in search of buried treasure. On the face of it, all is well. But look closely at the film's protagonists, with their strange vestigial features and blank, marbled gaze, and one comes to suspect that here, at last, is the version of Alph-Art we assumed would never see the light of day.
Officially speaking, The Adventures of Tintin is a conflation of three antique Hergé tales (The Crab with the Golden Claws, The Secret of the Unicorn and Red Rackham's Treasure), with the ambiguities ironed out and the emphasis on the action as opposed to the comedy. It shows how the boy reporter (played here by Jamie Bell) plucks a model ship from a bric-a-brac stall and immediately finds himself targeted by all manner of gun-toting goons. The ship, it transpires, contains a rolled parchment that points the way to a long-lost stash of gold and jewels. Along the way, Tintin hooks up with Captain Haddock (Andy Serkis), the turbulent, whisky-sozzled descendant of seafaring nobility, now kept as a virtual prisoner aboard his boat.
In one superbly executed sequence, Tintin, Haddock and Snowy the dog must steal into the cabin to pluck the keys from the hand of a sleeping sailor as the ship rolls and pitches in a heavy sea. Except that once inside, Haddock keeps groping for an elusive bottle of whisky and Snowy for the uneaten sandwich on the upper bunk. Only Tintin – as ever, an emblem of resolute virtue – has the presence of mind to go straight for the keys.
Yet while the big set pieces are often exuberantly handled, the human details are sorely wanting. How curious that Hergé achieved more expression with his use of ink-spot eyes and humble line drawings than a bank of computers and an army of animators were able to achieve. On this evidence, the film's pioneering "performance capture" technique is still too crude and unrefined. In capturing the butterfly, it kills it too. What emerges is an array of characters (puffy, moribund Haddock; opaque, inexpressive Tintin) that may as well be pinned on to boards and protected by glass.
Viewed from a distance, The Adventures of Tintin stands proud as freewheeling, high-spirited entertainment. But those close-ups are painful, a twist of the knife. There on the screen we see Hergé's old and cherished protagonists, raised like Lazarus and made to scamper anew. But the spark is gone, their eyes are dusty, and watching their antics is like partying with ghosts. Turn away; don't meet their gaze. When we stare into the void, the void stares back at us.
• In cinemas from 26 October
