Project Sylpheed: Arc of Deception

The game's story takes place in the year 2632, five hundred years after humanity left the solar system. Under Earth's rule, 11 different star systems have now been terraformed and colonized. However, there are a number of groups who object to Earth's rule and desire independence, forming a rebel group called the ADAN Freedom Alliance. Following a suspicious accident, Margras joins the opposing ADAN forces to fight against his former friends and home planet. (mobygames)