This book has been sitting on my shelf for a while, but I finally pulled it down while in search of reading matter the other day, remembering or being reminded as I did so that it was Lethem's first novel, and that he seems to have acquired a lot of semi-mainstream literary credibility in the years since it came out.
The blurb and interior review quotes lead me to expect a mixture of hard-boiled detective story and dystopian SF, which I got, but the book is perhaps even more significantly an example of School Of Philip K. Dick. Dick's influence on a certain sort of highbrow American genre SF writer is huge, and Lethem here has exactly that Dickian tone of faintly surreal, sun-bleached futurism, and a very large dose of the Dickian (literary) interest in mind-altering drugs. The blurb also lead me to expect something funny, which I didn't get; the Dickian quasi-surrealism, and especially the talking animals which loom large in the plot, might have a certain Pythonesque quality, but any laughs are lost in the noir-meets-dystopia looming darkness of the setting.
The detective story elements, by the way, reminded me of the movie Brick; they treat numerous tropes of the classic Hammett/Chandler movies as a kind of modern Commedia Dell'Arte framework, to be reused on the assumption that the audience will recognise them. Though I have to say that I enjoyed Brick more. Nor is the mystery plot especially strong; eventually, the hero solves his case, but mostly by coming up with a story which arguably fits the facts marginally better than anything else available, and which is more satisfying to the lead characters' sense of the world.
I should also note that the SF elements of this novel are, in true Dickian style, subservient to the other aspects; the dystopia is low-key and mostly a matter of a world slipping down to noirish moral corruption, and the furniture is very consciously retro. Even in 1994, when this book appeared, the complete absence of mobile phones and the limited use of computers - all accessed through monochrome terminals rather than PCs - must have looked a little odd. But futurism isn't the point here. Anyway, it's a smart book, but not one I can love.