The 15:17 To Paris - a funny way to celebrate heroism (Movie House from 9 February)

Two and a half years ago, three Americans intervened during a violent attack on a train from Amsterdam to Paris. Clint Eastwood cast the men - Spencer Stone, Anthony Sadler and Alek Skarlatos - as themselves in The 15:17 to Paris, recreating the incident and celebrating their heroic actions.

The school friends, two of whom joined up to serve in the US military, had met up in Europe to go backpacking. Having been through Venice, Berlin and Amsterdam, they dithered about going to Paris. The film dips in and out of their school days and military training, using rather effective child actors before switching to the actual people.

The film nearly spends longer watching the guys choose a flavour of ice cream to eat and debate whether to travel to Paris than recreating the attack on the train. In fact, the incident is rather secondary to Eastwood's determination to gently show off their bonhomie and companionship.

Unexpectedly, The 15:17 To Paris passes the 'six laugh test' with dialogue that is so bad that I wondered whether it was written to distract from the acting. At one point in his less than auspicious training, a dejected Spencer Stone says: "I just wanted to go to war and save lives".

At various points during the 94 minute cinematic experience I wondered whether the whole film had been improvised, and whether all the first takes had been edited together to make the movie. The 15:17 To Paris could be a contender to take over from The Room!

"Ever feel that life is catapulting you towards something?" asks Spencer. Anthony Sadler quotes the line back at him later in the film, in case we didn't get the hint first time round.

A Berlin tour guide castigates the confused trio (around a mix up over Hitler's place of death) saying "You Americans can't take credit every time evil is defeated". No irony is acknowledged even though the film's tight focus on the three Americans somewhat reduces the light shone on citizens from other countries who also intervened on the train.

For a while I thought Eastwood was going to 'do a Dunkirk' and not allow us to see the face of the gunman. In the end we do, briefly. But there's no attempt to fill in any of Ayoub El Khazzani's background. This is about the three Americans.

The best performance in the film is given by French President François Hollande in a speech he delivers while awarding la Légion d'honneur to four men standing on a podium in the Élysée Palace. Real footage from the ceremony is cut in with scenes filmed with the rest of the cast. The President is clearly a public speaker, a performer, and has a good scriptwriter. Eastwood should have sought out the speechwriter to soup up the screenplay. La pièce de résistance is bien sur of course the fourth man on the stage. A fourth brave soul who wasn't American and leaves the audience wondering why he's up there.

Don't forget to sit on through the credits for the extra scene that is squeezed in. If you miss it, don't worry. It doesn't garner any more laughs: you've had your lot by that point.

Why this cringe-fest was released as a movie is beyond me. The experiment to allow three likeable-enough lads represent themselves on the silver screen is laudable. But the result is that Clint Eastwood creates a whole new genre of film: accidental pastiche hero comedy.

The 15:17 To Paris will be screened in Movie House Cinemas from Friday 9 February. It's so bad, I'd nearly recommend you see it.