The Sonic Generations is now available on Xbox Live and the Playstation Network which includes the classic Green Hill Stage. None of the newer levels are in the demo. Here is the kicker; Sonic Generations will only be available for 20 days and there is no tricking the demo. It is set to expire after 20 after it was released. Being that you have to be connected to Xbox Live to download it, the game knows the date, so you have 19 more days to play it now.