AS well as being famous for such hits as Forrest Gump and Back to the Future, Robert Zemeckis has a reputation as an early adopter when it comes to high tech moviemaking. Not that it has done him a lot of good. The Polar Express, Beowulf, and A Christmas Carol, all ahead of their time experiments with performance capture – in which actors are blended with their computer-generated characters – looked just plain weird.

The true story of artist Mark Hogancamp, whose recovery from a vicious beating involved him creating the fictional Belgian town of Marwen and populating it with dolls that he then photographed, seemed ideally suited to Zemeckis. A case of cometh the story, cometh the man with the (by now refined) technology.

The two duly turn out to be a winning match. The problem this time is caused by tone rather than tech, and in particular an excess of schmaltz.

Zemeckis begins by running the legend “based on a true story” on the screen before cutting to a doll version of Steve Carell flying a plane over Belgium during the Second World War. Meet Cap’n Hogie, the alter ego of Hogancamp.

After crash landing, the captain goes in search of help but is discovered by a Nazi patrol. Just when it looks like his time is up, a miracle occurs in the shape of five machine gun-toting female dolls who make quick work of the Nazis.

Thus the stage is set for the continuing adventures of Hogie and his “dames”. Hogancamp’s Marwen, built in his backyard, looks like a model village, complete with painstakingly detailed interiors.

It is not just Hogancamp who has a fictional avatar. The five dames represent significant women in his life, albeit in highly sexualised form, including Anna, his Russian care assistant (Gwendoline Christie, Game of Thrones) and his friend Roberta (Merritt Wever).

Between medication and Marwen, Hogancamp tries to find a way back from the beating which wiped out most of his memory. It is now time for the gang to be sentenced and Hogancamp’s lawyer wants him at the hearing to convince the judge this was a premeditated hate crime and not a random attack. Hogancamp, drunk at the time, had earlier told the knuckle-draggers that he had a thing for wearing women’s shoes.

Taking his mind off the looming hearing is a new neighbour, Nicol (Leslie Mann), who is just as nice as nice can be. Soon, there is another resident of Marwen who looks strikingly like Nicol and is falling in love with Hogie.

Hogancamp’s story had already been told in an acclaimed 2010 documentary, giving Zemeckis a tough act to follow. He cuts back and forth from reality in the upstate New York town where Hogancamp and Nicol live, and Marwen, where Hogie is always ready with a wisecrack and wears his high heels proudly.

At first the clash of tales and tones works well, the broad gag of life in Marwen contrasting with Hogancamp’s gentle humour (he does love a pun) and obvious suffering. The audience gets the message about Hogancamp’s need to act out his trauma early on, but Zemeckis keeps returning to Marwen with ever more obvious pointers and explanations. If ever a story required delicate brush work it is this one. Zemeckis, however, keeps slapping on the primary colours.

Worse, he adds increasing dollops of schmaltz where once again it is not needed. Carell already brings a softness and vulnerability to the character, and the story, a man living in terror of the world, is a heartbreaker.

Though Carell gives a fine performance, the part needed someone more complex, less obvious. A Jim Carrey, maybe, someone to give it an edge. What we get instead is a mushy, softly rounded retelling of a jagged tale best told straight.