‘Excommunication is too good for him! I should boil him in his own drawing ink!” Pope Leo X (voiced by Toast of London’s Matt Berry) is very cross indeed with Leonardo da Vinci for dissecting cadavers. “It makes my stomach all queasy-weasy!” Berry’s papal peevishness is a spark of joy in an otherwise drab kids movie about Leonardo in his later years, made using a mix of stop-motion and hand-illustrated animation. It’s a bit of a bore and a chore, and feels like the kind of “educational” film that will be foisted on kids in class during wet playtime on rainy days.

The man himself is voiced by Stephen Fry (not bothering with an Italian accent; the script drops in the odd per favore and grazie to compensate). The film opens in Rome, 1516, and Leonardo’s scientific explorations have put him in hot water with the pope. Why can’t the old boy stick to painting “pretty pictures”, mumbles Leo X. So Leonardo accepts an offer from King Francis I of France to join his court.

There really isn’t much of a story after this in co-director Jim Capobianco’s script (he was Oscar-nominated for the screenplay of Pixar’s Ratatouille). In France, Leonardo soon discovers the young king is just another puffed-up preening monarch – Francis greenlights his plans for an “ideal city”, but only on the condition that there is a humongous statue of himself pride of place. In truth, Francis doesn’t give two hoots about science or progress.

That gives Leonardo plenty of time to poke about with dead bodies and ponder life’s biggies: why are we here? What is our purpose? Usually, these are the kinds of questions that kids love to chew on – but in places the film feels as lively as one of the corpses. The whizzing, whirring wonder of Leonardo’s mind never comes to life; maybe it’s the lacklustre script, or Fry’s donnish, dodderish performance. It doesn’t help that he looks more Father Christmas than Renaissance man.

• The Inventor is in UK cinemas from 8 March.