I decided to post MY review of Ender's Game, as I was afraid that Amazon.com or something of the sort would scare you away even more. But, you have to TRUST me, as I trusted my brother sooo many years ago.
Basically, the earth has been attacked and/or threatened 2 times by an alien species, which they call the "buggers." That has happened pre-book. The military decides that the best time to teach military strategy is in childhood through classroom settings and games. They have a specific testing set that they put each child through to determine if they have the right mix of traits to go to Battle School or not. Ender (who's real name is Andrew) is a child that is tested and taken up to Battle School. They are divided up in Battle School into armies in which they attend class, train, and play the games together. The most facinating feature of the novel is the Battle Room in which the government has figured out how to manipulate gravity to make this room null gravity where they do battles with special suits and lasers. The whole point of all of this is for the "teachers" to be able to spot good leadership qualities and such for future commanders. I really can't figure out how to say more without giving away too much. I'll just say that it becomes apparent by the way they rush some kids through the training that there is another battle with the buggers impending and they are in a hurry to get the best kids out of Battle School and on to Command School so that they'll be ready in time. Command school has more games and more lessons to learn.
HOWEVER, please don't get the idea that this is a book full of military jargon or that sort of thing. It really isn't. It's really about a boy that is trying to grow up way too fast because of the circumstances that he's put in and then trying to carry the weight of the world on his shoulders before most of us even knew that the world had any weight to bear. If you try this book out, please just keep reading it. It caught me straight from the get-go, but there are things that you have to figure out little by little, so it is easy to be confused and give up. Just keep reading and I really and truly think that you'll add it to your list of books that you'd recommend.
There are never any alien scenes or anything like that. There are never any "Nanu-Nanu" type things (Mork and Mindy if you don't get that reference). It is just a fun, imaginitive book by an extremely intelligent and creative author.
OK...I'll be done for now. If you have any other questions, let me know!