Dear, sweet Jesus. This book rocked. First off, the story is simple yet complex. The prose is clear and concise. Card cuts to the core of truth about the group dynamics of children--and I dare say, adults--with a few well-turned phrases. He showed me how siblings could love and hate each other at the same time. He made me believe that Ender could command a military offensive at the age of ten, just as I believed Ender's 12-year-old sister Valentine and their 14-year-old older brother Peter could influence world events over the internets. I believed that a kid could be made into a machine. I believed a machine could still love. Sure, there were a few things that were a little off--relativity and space travel among them--but I was willing to suspend disbelief long enough not to care. This one is near of the top of my "favorite books" list. Highly recommended.
The edition I read had a lengthy introduction. I've read (more like devoured) author intros as long as I've been reading books. This one was a particularly good one in that Card mentioned the book had been used in the classroom in several different ways: military leadership classes, literature classes, religious discussions, etc. He wrote something that touched me deep to my writer core, and I share it with you here (I'm also going to put the quote at the bottom of the page, for those that venture that far): "The story of Ender's Game is not this book, though it has that title emblazoned on it. The story is the one that you and I will construct together in your memory. If the story means anything to you at all, then when you remember it afterward, think of it, not as something I created, but rather as something that we made together."