This has to be, hands down, one of the best science fiction books written. Ender's Game is set in a disarmingly straightfoward sci-fi setting: a near future earth threatened by a hostile alien species with superior technology that seems determined to destroy the human race. The story centers on a young boy who is drafted into an all-consuming military training program at the age of 6. The program he's inducted into seeks to forge a new generation of military commanders out of gifted children, and it's sole purpose is to break them at any cost, until they finally discover someone who can't be broken. What follows is an emotionally complex and at times painfully familiar story of children struggling to accept their inner demons. Ender in particular is cursed with a brutal combination of profound empathy for others, and an overwhelming survival instinct that drives him to win no matter what the cost. It is this combination of gifts that may make him the commander the fleet needs in it's war against the alien invaders, but only if Ender can find a way to survive the burden of understanding his enemy so thoroughly that he can no longer see them as "the other," but as a reflection of himself.
The story is fast-paced, and Card's signature style of simple, plain language and streamlined descriptiveness serves to bring the characters front and center at all times. This book is infused with a very real sense of psychological and spiritual dislocation, and treats it's young protagonists as fully realized, intelligent, 3 dimensional characters struggling with very adult questions. Card's other signature: creating drama through ethical dilemmas, is also a central element of the story, and he does a very good job of challenging the reader to find some semblance of moral high ground anywhere. The conflicts between characters are made all the more powerful by the almost total lack of mystery: motivations and intent are laid out very clearly in most cases, and it is the reader's ability to empathize with everyone's point of view that makes the story less about winning and loosing and more about living with the consequences of either.
This book is thought provoking, emotionally complex, and ethically challenging. It's a powerful examination of conflict and violence, military necessity, family roles, and the ways in which we use the idea of "the other" to justify all manner of savagery.