Final Fantasy II (ファイナルファンタジーII Fainaru Fantajī Tsū?) is a fantasy role-playing video game developed and published by Square (now Square Enix) in 1988 for Nintendo's Family Computer as the second installment of the Final Fantasy series. The game's story centers on four youths whose parents were killed during an army invasion by the empire of Palamecia. Three of the four main characters join a rebellion against the empire, embarking on missions to gain new magic and weapons, destroy enemy superweapons, and rescue leading members of the resistance. After defeating the empire and the Emperor, the trio discovers that the fourth youth, now a dark knight, has taken the place of the previous emperor and is preparing to attack the rebellion. Upon confronting him, the Emperor reappears as a demon and prepares to destroy the world. However, the four characters agree to join forces to defeat him, and ultimately they destroy him in his demonic castle. The Game Boy Advance remake adds a bonus story after the game is completed, following several side characters who died during the game as they attempt to defeat an alternate version of the Emperor.