This is billed as a family film, but despite not watching it 'en famille' and with no children in sight, I still enjoyed it very much. The (considerable) charm stems from its rather old-fashioned feel, rather like the neverland world of 1950s and 60s school-based children's stories here. The film is based on an established series of French books for children, illustrated a la Quentin Blake.
The children are very amusing archetypes: the greedy one (who eats in every situation); the goggle eyed swat, whose arm is almost permanently hoisted at 12 o'clock to answer any question; the class ignoramus (though he knows more than it seems if asked in the right way); the rich boy, for whom walking to school is being carried by the chauffeur, the eponymous hero whose parents are as foolish as the children, and so on. The adults are very much the same, broad brush figures. The plot centres on childhood misunderstandings to do with the arrival of siblings and the utterly implausible but amusing steps the children take to subvert the arrival of Nicolas' new brother. (The children in the story look to be 10 or so but none has any understanding of 'the birds and the bees'!) No one is truly unpleasant:even the strictest teacher helps out with lines which are proving too time-consuming for the pupil.
Visually, the film has a delightful patina of the storybook, a little like 'Amelie' or the heightened polish of 'The Truman Show', though obviously at the service of a very different kind of story. This enhances beautifully the artifice of the whole production.
Great fun, though I have to say I wonder if it might be more enjoyable for adults brought up on the now rather dated fare of the 50s and 60s.