Did you guys here about the Sonic Generations Demo you can get on the PlayStation Network/Xbox Live Arcade?

This unique 20 day demo gives fans the chance to sample the most iconic environment of all Sonic the Hedgehog™ titles, Green Hill. The level from the upcoming Sonic Generations has been redesigned in stunning high definition and will be available for download in all its Classic Sonic side-scrolling glory and is also playable in stereoscopic 3D. There are only 16 days left.