After a decidedly lukewarm reception to the first instalment in its planned episodic series, Sega is already wheeling out the changes for Sonic 4: Episode 2.
For starters, you've already got a sidekick. Tails will be in the game. As for bad guys, Metal Sonic will also be in the game.
Sega also says that, in response to fan feedback (ie complaints), Episode 2 features not only a new graphics engine, but a new physics engine as well.
It also looks like there's been some platform changes, as at the conclusion of a short teaser trailer there are platform logos for practically everything, from consoles to handhelds, with the exception of the Wii. Which got Episode 1. Then the Sega rep announces the platforms again, and mentions practically everything but the Wii. So if you got Episode 1 on Nintendo's console...sorry?
You can catch the teaser trailer in the informercial below.