Sonic Generations is a hybrid of the series' classic 2D and more recent 3D adventures. It has classic levels rebuilt in HD. The full game is due late 2011.
"Sonic’s universe is thrown into chaos when a mysterious new power comes into force, creating ‘time holes’ which take Sonic and his friends back in time," goes the blurb.
"Whilst there, Sonic runs into some very familiar characters from his past including a younger version of himself! Now they must team up to defeat their enemies, save their friends, and find out who is behind this diabolical deed."
Sonic Generations can beto download to your Xbox 360. The demo weighs in at 652.54MB. Sonic Generations releases on Xbox 360, PS3, Nintendo 3DS and PC November 22nd. It explores 'Classic, Dreamcast and Modern' Sonic.