In the fight between heroes and villains, will you choose to save the world or conquer it? 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!