Ender's Game, written by Orson Scott Card, is a classic science fiction novel that follows the story of Ender Wiggin, a young boy who is recruited into an elite military academy in space to prepare for an alien invasion. As Ender trains and faces increasingly difficult challenges, the book delves into themes of leadership, morality, and the consequences of war. With its complex characters and thought-provoking narrative, Ender's Game is a compelling space-themed novel for older kids who enjoy exploring ethical dilemmas and strategic thinking.