is a platform video game developed by Sonic Team USA and published by Sega. It was the final Sonic the Hedgehog game for the Dreamcast after Sega left the home console market. It features two good-vs-evil stories: Sonic the Hedgehog, Tails, and Knuckles the Echidna attempt to save the world, while Shadow the Hedgehog, Doctor Eggman, and Rouge the Bat attempt to conquer it. The stories are divided into three gameplay styles: fast-paced platforming for Sonic and Shadow, multi-directional shooting for Tails and Eggman, and action-exploration for Knuckles and Rouge. Development began soon after the American release of Sonic Adventure in 1999 and lasted 18 months. Sonic Adventure 2 was produced in commemoration of the Sonic series' tenth anniversary and was designed to be faster-paced and more action-oriented than the original. The development team also expanded upon the presence of the Chao creatures and other player characters. Its locations were influenced by American locations such as San Francisco and Yosemite National Park. Sega announced Sonic Adventure 2 in October 1999 and exhibited it at E3 2000. It was released on June 19, 2001 in the United States, then worldwide on June 23, 2001. Sonic Adventure 2 received generally positive reviews for its gameplay variety, visuals, and audio, though some criticized its camera, voice acting, and plot. It quickly became a cult game, and an enhanced port for the GameCube, Sonic Adventure 2: Battle, was released in late 2001 in Japan and early 2002 in North America and Europe; it features improved textures and multiplayer options. Together, the Dreamcast and GameCube versions sold more than copies worldwide. Sonic Adventure 2 was also released as a downloadable game for the PlayStation 3, Xbox 360, and Windows in 2012. Gameplay Sonic Adventure 2 is a 3D platform game divided into two campaigns: Hero and Dark. In the Hero campaign, players control Sonic, Tails, and Knuckles, who fight to save the world; in the Dark campaign, players control Shadow the Hedgehog, Doctor Eggman and Rouge the Bat, fighting to conquer it. Each campaign cycles through levels of its three characters, telling different sides of the story. Levels have a variety of themes (such as cities, jungles, desert pyramids and outer space), with some followed by boss fights. The two campaigns' stories occur in parallel; completing both campaigns unlocks a final story with all six characters, culminating in a final boss fight. Sonic and Shadow