Sonic Adventure 2 was released in Japan for the Sega Dreamcast, marking the launch of the game.
The game was released in North America, expanding its reach to a wider audience.
Sonic Adventure 2 became available in Europe, further increasing its international presence.
An enhanced port titled Sonic Adventure 2 Battle was released for the Nintendo GameCube, featuring additional content and improved graphics.
Sonic Adventure 2 Battle was released on Xbox Live Arcade, making the game accessible to a modern console audience.
Professor Gerald Robotnik creates Shadow, an ultimate life form, aboard the Space Colony ARK.
Gerald conducts experiments on the Space Colony ARK, including trying to find a cure for his granddaughter Maria's illness.
Maria Robotnik sacrifices herself to save Shadow and urge him to protect humanity, after being killed during a military raid on the ARK.
After Maria's death, Shadow escapes the ARK and enters a self-imposed hibernation until he is awakened years later.
Dr. Eggman discovers and awakens Shadow to help him in his plans to conquer the world.
Sonic battles and calms Chaos, a water guardian awakened by the ARK's descent to Earth.
Dr. Eggman attempts to use the ARK's Eclipse Cannon to destroy Earth.
Sonic, Knuckles, and Tails form the Hero team, while Shadow, Rouge, and Dr. Eggman form the Dark team.
Sonic and Shadow join forces to defeat bioweapons Biolizard and Perfect Chaos to save Earth from destruction.
Shadow uses the power of the Chaos Emeralds to stop the ARK's fall, seemingly sacrificing himself in the process.
Shadow survives, choosing to live a new life on Earth after the ARK incident.
