If films got medals for bravery, Belleville Rendez-Vous would be handsomely decorated. For starters, it’s a cartoon – and even in these enlightened times, the stigma lingers that cartoons are, well, for kids. It’s also French, and almost totally free of dialogue. It’s a shame, though, if that’s an off-putting combination, because this has much to recommend it to a grown-up audience. It’s an eccentric, barmy piece of work that’s genuinely difficult to categorise – in a good way – and which feels distinctly like a labour of love. It’s hard not to feel affectionate right back at it, too.

The actual plot’s rather spindly, concerning a dedicated young bicyclist who’s kidnapped for nefarious purposes, only for a rescue attempt to be launched by his diminutive granny and his faithful dog. There’s also the matter of aging swing act The Belleville Triplets, who lend their weight to the cause. It’s rather loose and freewheeling, and the real joy here is in the details. The animation is teeming with flair and character, a different beast altogether to anodyne Hollywood studio fare. It sports a singular vision, gentle and old-fashioned in tone but pleasantly funky with it. The tale’s played out in neat set-pieces and little motifs run throughout – Bruno the dog’s dream sequences, the Triplets’ signature tune – and the effect is almost hypnotic, especially when devoid of dialogue.

The overall look is consciously retro. It wears its Gallic heritage well. The visual comic hi-jinks echo the films of Jacques Tati, and the lushness owes something to the imaginative filmscapes of Jeunet and Caro. As far as our shores as concerned, the parade of elaborate inventions and chase sequences has much in common with Nick Park’s Wallace and Gromit shorts, albeit more knowingly sophisticated. It’s certainly no barrage of belly-laughs; the humour’s soft and affectionate, and quite slapstick in nature. But it does well to rein in its excesses and find time for calmer interludes amongst all the craziness. By contrast, Spirited Away (2003) seems to try too hard to dazzle viewers with the breadth of its imagination and loses sight of the fact that it barely makes sense.

Chomet’s nutty picture-book is such an effortlessly charming piece, it seems almost churlish to fault it. It does, admittedly, feel like an overlong short rather than a snappy feature in parts. The plot, and the gentle humour, aren’t always quite compelling enough to grip the attention firmly. There are fleeting moments, too, when the animation looks more computer-based than handcrafted. Undoubtedly heavy technology’s been used throughout and the organic feel’s just a neat trick, but it’s a shame when the trick becomes transparent. And despite being virtually silent, there are instances when, for example, a television news report plays out quite audibly in French, that may leave all but multi-linguists feeling they’re missing something.

But these are just niggles. The overall result’s genuinely unusual and imaginative, perhaps an acquired taste, but one which is certainly worth discovering. Is it a children’s film? It hardly seems to matter. It bears a 12A certificate, but there’s little here for youngsters to be wary of. At heart, it revels in the much-underrated notion of being fun for all the family. It’s often perfectly mental, mesmerising and irresistibly loveable.