Before I begin my review, a statutory warning to all my patriotic Indian brothers and sisters... this is India-bashing, large scale. If you are the sort of person who gets all worked up when any aspect of India is criticised, this book is not for you.
That said, Arvind Adiga bashes India where it has to be bashed. No honest reader will be able to dispute that the picture of India he paints is a false one. You will find the majority of Indians embarassedly changing the topic when Bihar (the state Adiga names "Darkness") enters the conversation. Most of the things he mentions are not only possible, but probable and even likely. You only have to read any Indian newspaper over the period of a week to know it.
But I believe the author fails in the creation of Munna alias Balram Halwai, the protagonist, because his voice is totally out of character with the person. It is the supercilious voice of a Westernised Indian, detached from his home country by education and station in life that comes through. The street smart Munna who murdered his employer and set up his business in Bangalore will talk in an entirely different way (for example, he will never say "five hundred thousand rupees" - he'll say "five lakhs"). Here, the character just becomes a mouthpiece for the author.
Secondly, Adiga goes overboard in criticising India, so that some of his examples become rather extreme (the immediate one that comes to mind is the schoolteacher boozing and sleeping in the classroom). In some other cases, they are downright silly (Balram buys a dosa and throws out all the potatoes before giving to Mukesh, whereas he could have bought a dosa easily without the potatoes: these are two varieties). It also confirms the opinion I formed of Adiga from his bio that he is that type of Indian Lord Macaulay wanted to create: Indian only by birth but English in spirit.
Lastly, the story failed to hold my interest. Take out all the social criticism and it is nothing but a hollow shell. And the gimmicks, like framing it as a letter to the Chinese premier, are trite to the point of being nauseating.
The only thing that forced me to give two stars to this work is some of the pithy statements Adiga makes about Indian society. Especially the ones about how caste-ridden India was a zoo, with all animals in separate cages when the British let them all out, so now only the ones with the big bellies and the ones with the small bellies are left; about automobile horns during a traffic jam joining together to form a single wail like a lost calf wailing for its mother; and the one about how the major diseases India faces are cholera, typhoid and election fever (though I would also include cricket).