Sonic turns 20 years old on June 23 and Sega is handing out a Sonic Generations demo as a party favor. Download it and you can play Green Hill Zone Act 1 with Classic Sonic.
Sega plans to release the demo in multiple regions, but only for a limited time. Reports from Japan note distribution of the Sonic Generations demo will end on July 12. Also, Xbox Live free members have to wait a week before they can download the 653 MB file.