Its an good Soft sci-fi (meaning it is not much concerned with laws of physics) and tells us the Story of Ender, a boy who is forced to become an commander of earth forces against invading forces. Sounds a bit Cliche’d? Well it is but story is told so well that you wont notice that. Also instead of making invasion main focal point the story is actually heavily focused on Ender and his military training. Though some parts of story seem ludicrous now eg. Ender’s brothers rise.
All in all an good story propelled into list of classics by excellent story telling.