If you are playing the stock disc or standard digital install, you are missing out on a significant chunk of the game. The DLC adds three major components:
The following major DLC pack was released specifically for the Xbox 360: Metal Sonic & Outrun DLC Pack Metal Sonic dlc sonic all stars racing transformed xbox 360 rgh
Copy your DLC container files into the 00000002 folder using a tool like Aurora's File Manager or XM360 . If you are playing the stock disc or
For users of a modified (Reset Glitch Hack), accessing and installing DLC for Sonic & All-Stars Racing Transformed dlc sonic all stars racing transformed xbox 360 rgh