Even ardent Stephen Chow fans may be nonplussed by CJ7, a throwback to sentimental comedies about children that were in vogue a generation ago in Hong Kong. Chow, who got his start hosting a kids' show on television, reaches back even further, specifically to the Dickensian melodrama of Charlie Chaplin's The Kid. It's a daring and not entirely successful leap for someone best known here for the rambunctious, freewheeling Kung Fu Hustle.

Nominally the star, Chow takes a backseat role in CJ7, playing Ti, a construction coolie thrown into a tailspin by the death of his wife. A squatter in an abandoned, collapsing tenement, Chow is literally starving to death in order to send his son Dicky (Xu Jiao) to an expensive prep school. Ostracized by his wealthy classmates, failing in his subjects, and too poor to afford even sneakers for gym class, Dicky still tries to live by his father's moral code. He becomes the unwilling champion of other outcasts at school, a position that paradoxically makes him even more unpopular with the elite.

Dicky throws a tantrum when Ti refuses to buy him a pricey new electronic toy. Trying to make up, Ti brings home a strange object he found in a junkyard. To Dicky's initial fear and eventual delight, it turns out to be an alien with superpowers. "I'm going to be rich," is the boy's first thought, and in an amusing dream sequence he uses his new pet to win fame, vanquish his opponents at school, and accumulate luxury items. Reality is a bit more complicated, as CJ7, a sort of glowing plastic puppy, only helps when he wants to, and often ineffectually at that.

Aimed squarely at kids, CJ7 is less exuberant and unpredictable than most of Chow's work; it also has a heavy streak of moralism that can get tedious. The film replays some classic bits from recent Chow hits, as performed by kids. Weirdly, it also resurrects a scatological subplot from God of Cookery that most parents here would find objectionable for children.

There's no questioning Chow's commitment to the material. He shot it near his hometown outside Shanghai, and his empathy with the poor in the picture reflects his own underprivileged upbringing. He elicits exceptional performances from the child actors, in particular Xu Jiao, a young girl who plays, very convincingly, the part of his son. Chow himself is extremely winning whenever he is on screen, but this is first and foremost a kids' film, not a vehicle for the one of the best comics currently working in movies.

Released for the Chinese New Year, CJ7 was a huge hit across Asia, where its message of respect and tolerance for the poor found an enthusiastic audience. With Chow still a cult name here, it will be tough persuading viewers to take a chance on a small-scale children's film, no matter how well-made.