Its a book that really makes you think. You have to think in unconventional ways, with a range of diagrammatic approaches to solve problems that look pretty on paper. The text is sometimes too dense, however, and the problems serve to illustrate every different scenario possible under the analysis, which means that no two are ever alike, however if situations are similar the answers required can be also. Owing to the dissimilarity of questions, its not necessarily the best book one can revise from (for exams), as an important component for exams is getting a feel of the type of questions through repetition.
Another MAJOR BUMMER is that the author refuses to give out the answers. He grants permission to Game Theory teachers to give out hard-copies, but given that the answers take up 200 pages some teachers are (understandably?) apprehensive to printing out such paper as they only require their students to answer a selection of questions. The problem is if someone is independently studying, they have no way to check their progress. However, someone has kindly uploaded a scanned copy of the answers on a torrent site (search for An introduction to Econometrics), and it can be downloaded (though I'm not sure of the legality of this).
That said, the text is dense and you have to wade through the specialised notation, but once you solve a problem successfully, it makes the high that much more.