The hunt for the Chaos Emeralds is on and battle lines have been drawn between Hero and Dark. Experience two unique adventures featuring both long-time heroes and new and returning villains as they battle for the fate of the world! -Save the day as heroes Sonic, Tails, and Knuckles or cause chaos as Shadow, Dr. Eggman, and Rouge, utilizing each of their unique skills and abilities! -Take a break from the main story and challenge a friend in two-player across kart racing and other competitive modes! -Raise your own pet Chao, improve their statistics, and compete with them in unique mini-games! -Challenge yourself to complete over 150 unique missions across 30 action filled stages!