Ender's Game - Orson Scott Card

Science fiction! Space! Aliens! War! Dystopia!
This novel won a Nebula award and a Hugo award, which are pretty BIG THINGS in the world of science fiction literature. For once, I agree with the bestowment of awards; this was a very good, heart-wrenching novel. I was (figuratively) glued to this book's 226 pages.
It follows the life of this boy, Ender, who is a Third, a third-born child. Now, this takes place in (where else?) a dystopian future, where overpopulation has made it necessary to limit the number of children allowed; two children per pair of parents is the limit. Ender, however, was allowed to be conceived because Earth needs a military genius, and through unexplained genetic modification two people who were almost good enough were made: Ender's older brother, Peter (too sadistic), and his older sister, Valentine (not violent enough).
When he is six years old, Ender is taken to the Battle School, where gifted children are essentially taught and conditioned to be the soldiers Earth needs. There, he proves to be a tactical genius, and after five years of training and growth, he commands Earth's starship force and destroys the alien menace. However, he did so without knowing he was commanding actual spaceships against the actual alien enemy; he was manipulated to believe it was a big simulation, a big game.
Now that almost all the spoilers have been revealed (not gonna apologize), let's look at a few things that bothered me about his novel, shall we?
First, there were very few girls at the Battle School, because "centuries of evolution" were "working against them" (p.17). Part of it is true; we do have centuries of social conditioning that have instilled the idea that girls are "mild" and "soft" and "meek" - but evolution itself has nothing to do with it. In fact, how do you think girls can be so cruel, psychological-, emotional- and social-bullies, especially when they have a little posse to support them? It's because girls are even more severely punished than boys when they resort to physical violence, aggressiveness needs an outlet, and psychological and emotional bullying are much more "acceptable" ways in which girls can be total assholes.
Second, all the kids at the Battle Academy did not sound like children; those were adults, or at least teenagers speaking, but the characters were all under twelve years old. But I guess this was the point; these children, training to be soldiers since they were six years old, could not possibly have had any childhood... Which is what made this novel so heartbreaking.