The blue hedgehog and the red echidna were sworn adversaries in Sonic 3, but in this platform adventure, Knuckles realises that he’s been just a pawn in the schemes of Dr. Eggman (AKA Dr. Robotnik). Knuckles, the former adversary now supports Sonic to chase the common enemy, and each must use their strengths in order to acquire the priceless Master Emerald and save Angel Island. This game requires the Xbox 360 hard drive or the 512MB Memory Unit for storage. There are no refunds for this item. For more information, see www.xbox.com/live/accounts.