Sonic Generations demo today?

Andriasang is reporting that Sega will release a demo of Sonic Generations on June 23, which will give players a chance to try the first act, the classic Green Hill Zone, using the “Classic Style” play style, and will even support stereoscopic 3D. The downside? The demo will only be accessible for three weeks, after which it’ll expire and no longer play.

On July 12, the demo will disappear from PlayStation Network and Xbox Live Marketplace, and downloaded versions of the demo will no longer run. A problem asides with Japanese PS3 users, as PSN is still not live in Japan, and the demo’s expiration date applies to all PS3 regions. Therefore, if PSN is not restored by July 12, tough luck, Japanese gamers.

On the Xbox 360 side, the demo won’t be available to non-Gold members until a week later on June 30.

Sonic Generations launches on July 13 on Xbox 360 and PlayStation 3.