Much of the humour comes from Bramah's language, which is elaborate, ornate, and deliberately taken to excess, full of long sentences, circumlocutions, honorifics, euphemisms, et cetera (and no doubt for some people ad nauseam). Here are a couple of typical sentences:
"the sentiments which this person expressed with irreproachable honourableness when the sun was high in the heavens and the probability of secretly leaving an undoubtedly well-appointed home was engagingly remote, seem to have an entirely different significance when recalled by night in a damp orchard, and on the eve of their fulfilment"and
"Tiao had in the meantime accepted the wedding gifts of an objectionable and excessively round-bodied individual, who had amassed an inconceivable number of taels by inducing persons to take part in what at first sight appeared to be an ingenious but very easy competition connected with the order in which certain horses should arrive at a given and clearly defined spot."This style is maintained throughout.
Bramah deploys a mix of satire, parody, and slapstick, all delivered deadpan. He also has a good line in invented names and fanciful proverbs sourced from imaginary authors and books. There is much mockery, but it is all light-hearted and without malice.
The Kai Lung stories must surely have been an influence, even if an indirect one, on modern comic writers such as Barry Hughart and Terry Pratchett, and should appeal to their fans. The style takes some getting used to, but The Wallet of Kai Lung is actually really easy reading. I had the good fortune to borrow it from the library just before coming down with the flu and it proved most comfortable sickbed entertainment.