Sonic the Hedgehog 4: Episode I, the long-awaited return to 2D gameplay for the Sonic series, met with a mixed reception when it debuted on consoles in 2010. The Windows Phone version debuted several months later. In WPCentral’s Sonic 4 review, I praised its faithfulness to the console game (outside of a crummy pinball level exclusive to the mobile game) and touch screen controls. While the retro remake of Sonic CD is still due to arrive sometime (having already hit consoles and iOS), many fans have been left wondering about the fate of Sonic 4: Episode II.

Good news today then, as Sega has finally released a teaser trailer for Episode II. The trailer is devoid of gameplay footage, but it does at least promise the return of two popular characters: Tails the fox, Sonic’s young sidekick, and Metal Sonic, one of the main enemies in Sonic CD.

Head past the break for another video and more gameplay details!

In addition to the teaser, Ken Balough (the Sega staffer who WPCentral previously interviewed about Sonic CD) discussed some of the changes coming to Episode II in a video interview with GameSpot. The second episode of Sonic 4 will sport both an all-new graphics engine and all-new physics engine. The new physics will hearken back to the original Genesis Sonics, fixing one of the main criticisms of Episode I. Balough doesn’t confirm this, but it’s quite possible that Christian Whitehead’s Retro Engine, which powers the Sonic CD remake, is at least tangentially involved.

Sonic the Hedgehog 4: Episode II is coming to a variety of platforms, including Xbox 360, Playstation 3, Windows Phone, iOS, and Android. There won’t be a Wii release, but I doubt many people will be playing their Wiis after its successor, the WiiU, debuts in 2012.

Source: GameSpot