Leaked footage of Sonic the Hedgehog 4: Episode 1 has been published on the all-format gaming website, 1UP.

Shortly after 1UP posted the new screen shots and video of Sonic 4, Sega asked them to remove the content from their site.

In that short time, the screens and video footage were captured by many Sonic fans, helping confirm that the following levels would be in the upcoming game:

- Splash Hill Zone
- Lost Labyrinth Zone
- Casino Street Zone
- Mad Gear Zone

It has also been revealed that Sega’s Sonic Team will not be developing the blue hedgehog’s fourth official outing.

Instead, Sega have put Sonic 4 in the hands of Dimps. In the past, the Osaka-based developer has been responsible for the Sonic Advance and Sonic Rush games.
Sonic the Hedgehog 4: Episode 1 will be available on WiiWare, XBLA and PSN summer 2010.