In the first 5 minutes, the movie starts with smoking cartoon characters, a topless dancing woman wearing only, well, either bananas or leaves around her waist, and a bunch of tiny people come onstage and pull them off her. It started out excessively mocking of obese people, which had no relevance to the story, and then became sad and bizarre. Matter of fact, that entire scene had no purpose, as best as we could tell. As many "weird" movies I've enjoyed, both foreign and not, I can't understand how anyone could enjoy this.
I only watched it because of the good review from this website, but neither my daughter nor I found it fun nor cheery. It was astonishing, but not in a good way. I'm just baffled at the recommendation from this site.
But for anyone still wanting to watch it, don't be fooled by this site's review stating "The astonishing, outlandish, and singular originality of THE TRIPLETS OF BELLEVILLE defeats any attempt to describe or explain it." That's nonsense. It's a sad boy living with his grandmother and an increasingly overweight dog, with dead parents and a love of bicycles, who grows up to become an apparently professional cyclist, who is kidnapped by gangsters. Grandma and the dog get help and save the day. It's really not that complicated.