Here's my Amazon review of Enders Game.
Being new to the sci-fi genre (this is really the first sci-fi book I have read, if you don't count C. S. Lewis's Narnia series) I write this review with the knowledge that there are probably many things I don't get in this story. Therefore, this review will probably lack some of the depth that could come from a more knowledgeable reader. However, maybe as an "outsider" to the sci-fi genre I'll have a few worthwhile thoughts.
Ender Wiggin is a tormented child genius, charged with saving the earth from alien invaders. The book tells the story of how Ender is recognized as the potential "savior of the earth", how he is trained and how he ultimately defeats the alien invaders.
The plot is a good one, but the development of the character of Ender is the highlight of the book. When we first meet him, he is the kid who gets picked on by his evil older brother and the bullies in the neighborhood. Ender is a sensitive kid who doesn't want to hurt anyone. However, throughout the book he is put into positions where he has to defend himself. When he does defend himself he doesn't merely defeat his enemy, he destroys him. Then he feels guilty about it afterward.
The rulers of the earth monitor Ender and notice this, along with his brilliance in computer simulated war games. The earth has been attacked twice by alien invaders and nearly wiped out each time. The powers that be expect another alien invasion and so they conscript Ender into leading them in battle against these aliens.
While Ender is whisked away into outer space to be trained to save the earth, back on earth his evil brother Peter concocts a plan to rule the earth, and he conscripts his and Ender's sister, Valentine to join him in this. Peter and Valentine take on cyber identities of Locke and Demosthenes and interject themselves and their opinions into the affairs of the day, and eventually grow to wield great power on the earth.
There is a sense in which this is a psychological thriller because much of the story has to do with what is going on in Ender's head. Here he is, the sensitive young boy (did I mention he is only 10?) who is being taught to destroy others and eventually destroy an entire alien race. His interior wrestlings with this dominate the book. We also see him agonize with fears of becomgin like his brother Peter, and deal with the fact that the world leaders are using him.
The fact that the author chose the names Demosthenes and Locke for two of the main supporting characters is interesting. Demosthenes is an ancient Greek writer known for his orations against Phillip of Macedon and Locke is known for his anti-authoritarian views. Since I don't know what was going on in the head of Orson Scott Card when he was writing I can only speculate why he chose these names. As Demosthenes and Locke, Valentine and Phillip do, over time, undermine the existing authorities and raise themselves to levels of power. This hints at one of the subtle messages of the book, which is certainly seen in the case of Ender - you can't trust the authorities. In this book, the authorities can't be trusted. Demosthenes and Locke undermine authority, and Ender grates against the way he is used by the authorities.
There is a religious element to the book, albeit a subdued element. It appears that at the time of the story, religion has either been outlawed or done away with. Ender's mother secretly prayed, and if memory serves me correctly, may have even had the kids baptized or dedicated as small children. Rather than having faith, Ender is an object of faith in this book. In that sense, he is a kind of Christ figure, but only in a loose sense. He is the savior of the world. And, in fact, at the end of the book, he becomes the founder of a new religion. There is even a place in the book where, when wrestling with deeds he has done, he confesses to a real love for his enemies, which is a very Christian theme. At the end of the book, he finds that he is unable to return to earth, and goes off to colonize another world - his kingdom is "not of this earth," again a very Christian theme.
I admit these religious elements are only there in a loose sense, I am not arguing that Orson Scott Card was operating from any Christian or religous presuppositions, but it is still fascinating to me to see potential connections.
The story has a great and unexpected ending - I wouldn't have expected it. Overall, its an enjoyable book - probably good enough to make me want to read the next one. Who knows, maybe I'll become a sci-fi aficionado.