Single Player, HD (High Definition). Rocket Sonic, the fastest blue hedgehog on earth, through hair-raising loop-de-loops and dizzying dives past bubbling lava, waterfalls and on as you gather up Rings and stop Dr.Eggman's (AKA Dr. Robotnik) schemes for world domination! There are no refunds for this item. For more information, see www.xbox.com/live/accounts.