ESRB rating gives a bit more info on Sonic 4
The ESRB has rated Sonic the Hedgehog 4, and while that is a very common occurrence for games coming to market, what has made this especially worth telling you about, is some of the gameplay details mentioned in the listing.
Without further ado, here it is, via GoNintendo:
Rating summary - This is a side-scrolling adventure game in which players zoom through themed levels, collect gold rings, and jump on tiny robot enemies. Players earn points for collecting "power-ups" and freeing tiny animals that are trapped in the robots. During boss battles at the end of levels, players may encounter an arch nemesis in a mechanical device that gets charred and emits some flames when damaged.
Sounds like a good thing that the Sonic 3 Team and Dimps are both working on it.
Episode One is due for PSN, WiiWare, and XBL this summer.