Imagine a world where Scotland is an unknown, barbaric place (OK, perhaps that doesn't take a massive feat of imagination) and England stands alone against Germany in the second world war. The evacuation of Dunkirk has failed, and the Germans' invasion of this sceptred isle is imminent. Having tried and failed by land and sea, those ingenious Nazis finally succeed by tunnelling beneath the channel and rolling their tanks right out into Trafalgar square.

Further imagine that the Europe of the 1940s is peopled by Barbie Dolls, Action Men and various other humanoid toys. Next, I'd like you to imagine that a rag-tag group of soldiers, American volunteer airmen, country yokels and a farm labourer with abnormally large hands rescue Winston Churchill from London, and retreat to the lawless wastes of Scotland to make their final stand against the goose-stepping invaders.

And there you have Jackboots on Whitehall, first-time writer-director team Rory and Edward McHenry's idiosyncratic stop-motion, animated alternative history of one of the defining events of the 20th century.

Even if you can picture that in your mind, however, what you won't be able to imagine, and need me to tell you, is whether this film is any good, and worthy of your time. Alas, the answer is a fairly resounding no. The animation style, while distinctive and initially amusing, loses it's novelty fairly quickly, and it runs out of steam on the jokes front pretty soon too. It's funny for about 15 minutes, and probably just about watchable for another 15, but after that Jackboots... goes rapidly downhill, and gets more tiresome and less entertaing as time goes on.

A large part of the reason for this is that the story of Jackboots on Whitehall is weak, and simply isn't compelling or entertaining enough to hold interest. Too much time has been spent on crafting character absurdities and running gags and when these inevitably, and quickly, become boring, there's no strong narrative to fall back on. On the upside, though, accent fans may find some diversion in counting the number of accents employed during the film by Ewan McGregor. (Those who don't want to know the final score should look away now. The number of accents used by McGregor is: All of them).

The film, or parts of it at least, I can see working as an animated short, or perhaps in an episodic format online. Had it been funnier the animation is also the sort of thing that wouldn't have felt at all out of place on Channel 4's The Adam and Joe Show 10 years ago. But as a feature film in a cinema? No, sorry, doesn't pass muster. Give it a miss.

I decree this film to contain 2 out of a possible 5 units of filmy goodness.