For a kids book, I don't think that it was too bad. I thought the characters were pretty flat, the story was a bit repetitive at times and was unnecessarily long. Sadly, I thought his understanding of economic consents was particularly weak. For the most part, the book was filled with the standard critiques of the economic conditions in the third world. Complaints about sweat-shops, child-labor, pollution, exploitation, etc. While some of these things may be bad, as usual, there is very little examination on why they exist, other than to say that they are rich powerful people exploiting poor weak people. I am sorry, but I generally do not think that is really the case.
In addition, I thought that his understanding of arbitrage was particularlly weak. Sure, I think that he explained what arbitrage was fairly well. However, his critique of saying that it does not create any economic value was particularly ignorant. For example, he does not seem to understand that getting goods from one person that values something for $5 to someone that values it at $10 creates economic value. His chapter on arbitrage says that the "neighborly" thing to do would be for a person to work to bring these two people together for free. Under this argument, people should be willing to work at any economic activity for free, because that would be "neighborly". However, his entire book is about people wanting to get paid more, not less.
In one area of the book, he has a child worker that is attempting to create a union in India talking with another worker who says that it is not fair for a boss to be able to fire workers, while workers cannot fire a boss. However, this argument fails, simply because it is incorrect. A worker can very easily fire a boss, it is called quitting your job. Under such an arrangement, that individual that was your boss, no longer has any control over your life. In fact, may of the laws we have today, including union rules, make it harder for a boss to fire their workers, however, we have no laws that prevent a worker from firing their boss by quiting. Just imagine the uproar that would occur if a law was suggested that would prevent people from quiting their job unless there was a justifiable reason, just like the laws that many countries have that require a business to have a justifiable reason to fire a worker.
I think that the reviewer from Wired over sold this book. While I enjoy the video game aspects of the book, the poor economics and poor reasoning of the book is going to prevent me from reading this book again. For the most part, it was entertaining, but not enough for me to want to read it again. Perhaps if I was 15 years younger, or I knew less about economics, I would enjoy it more.