The pace and vitality of the prose alone should be enough to recommend this fantastic book, but there is so much more.
You have, from the outset, that unnerving sense that everything is not quite as it seems. Then, sure enough, the three characters you have just met fly off to an apartment block where they land on a window ledge before diving at a sleeping man's neck and sucking his blood. No, not vampire bats, but mosquitoes.
Later, we meet moth/humans, cockroach/humans, ant/humans - in fact, it seems that for every human level there is a corresponding insect. As a device, the insect world is a rich and creative metaphoric scythe which Pelevin yields masterfully, taking glancing blows at each of us as we're reduced to our insect role in the world. Some of us have our heads continually buried in the dirt, some fly blindly towards our destinies, others do nothing but work.
It is the way humans transform into insects that is most staggering though. Mostly without warning, but brilliantly woven into the particular situation as though the human/insect dual life were an everyday occurence, these transformations reveal the tenuousnous of the positions we rigidly occupy. In this way, the stories of insect transformation are strangely liberating, and yet at turns very sad as a careless hand flicking something annoying away from a face kills a mosquito, or a moth extinguished by the very fire it swarms towards confirms our transitory and rather arbritary existence.
What more can I say?