Amy Rose
The game has several two-player modes. Players may race on foot through new (or altered) levels, have shoot-'em-up battles in mechs, hunt for Master Emerald shards or race in go-karts. A few characters are playable in these modes, but not in the main game; Tikal and Chaos from the original "Sonic Adventure" are playable in the treasure-hunting game, as are Amy Rose and Metal Sonic in the foot-racing levels and mechs piloted by Chao and Big the Cat in the shooting levels.