ain. Sonic Adventure 2: Battle features faster action, all-new two-player games, and a branching storyline that lets you choose to save the world as the Hero side, or conquer it as the Dark side. Two new playable characters enter the Sonic universe -- a mysterious dark hedgehog called Shadow, and a jewel-thieving bat named Rouge. In the single-player mode, you'll go through more than 30 unique stages, which include everything from a forgotten pyramid, an abandoned military base, and a giant space station. Then there's the expanded two-player mode, which features 12 playable characters competing in new head-to-head games. All of this adds up to Sonic's biggest adventure yet!