I was initially very skeptical about seeing this, the trailer had put me off, giving the impression of a formulaic slapstick based, loser-centered comedy. Those elements are there, but are less than half the film, and as such work in the context of the rest of the film.
The story is of a gang of sharp-suited 1930s style gangsters deciding to go to war on a previously ignored slum, and the kung-fu masters who defend it. The central character, played by director Stephen Chow, is a cowardly loser who is trying to ingratiate himself with the gang.
A large number of the jokes are genre references; just as Ford, Kurosawa and Leone traded ideas across the Pacific 40 years ago, Chow acknowledges the development of the kung-fu film that has been carried over to the US and has been taken up by the likes of Tarantino and the Wachowski brothers. There are many direct references to the likes of The Matrix and Reservoir Dogs. The many fights are choreographed by Yeun Wo Ping, who worked on The Matrix and Kill Bill, they are finely balanced between being great Kung Fu fights, some totally over-the-top comic pastiches.
The film isn't perfect, while the visual gags are usually great, sometimes the script falls a little flat. Overall though, I'm glad I went to see it.