Here's a review I saw on the internet of Great Apes

Will Self has always had an ambivalent relationship with the novel. He doesn't write about character and admits that he finds plot 'boring', as a result his novels usually work off a single comic device or absurd concept, stretched to the limit through a vast vocabularly, endless metaphors and a scatological humour. Self's is a style that can be very visceral, funny and incisive, however, over the course of an entire novel it can become nauseous, tedious and dull. Self is better suited to short stories and journalism, forums where his flamboyant, potent prose and wild premises still have the ability to be shocking rather than tired and worn.
'Great Apes', Self's 1997 work released shortly after the scandal over the author taking heroin on John Major's private jet, combines both these aspects of his work into a great, fierce piece of satire.
Taking the Kafkaesque premise of a London artist, Simon Dykes waking from a night of bad coke and worse sex to find himself in a world where chimps have reversed roles with humans, the novel works best when describing the social hierachy of the chimps and their bizarre behaviour, using it as a device to show how similar the two species are.
Dykes finds himself in a secure unit under the supervision of emenient primate psychiatrist Zack Busner, the titular 'great ape'. Self goes to great lengths to describe Dykes' anguish and how insane he seems in contrast to the rest of the world. As the book progresses Dykes' belief in his own humanity is shown to be nothing more than the workings of delusional mind- chimps do indeed have global supremacy.
Mental illness and the problems of medicine are common Self themes and the book does raise interesting questions about the nature of madness and drug abuse, but here they feel thinly developed, as if Self is writing for his own amusement. For every funny line or comic invention there are vast amounts of unecessary and flabby writing, either concerning psychiatry, sex or divorce, that just come across as dull. Self has an incredible mind, at his best recalling, all at once, Martin Amis, Celine, Kafka and Carroll, but here he comes across more as a man writing really just to waste time, as if the novel was a bit of filler between magazine assignments and taking drugs. The satirical comment Self hoped to make, on modern art, on coke, on humanity, on whatever, never fully translates or is fully concluded. Self started writing, kept going and then finished, whether what he wrote was of real substance wasn't obviously of much concern to him.