Sonic the Hedgehog is being prepared for a 20th anniversary outing, with Sega confirming that the 1991 Classic Sonic will join Modern Sonic later this year across 2D and 3D-style levels.
The game will be released on Xbox 360 and PlayStation 3, with each Sonic getting his own specific special moves.
Classic Sonic can use the Spin Dash and Spin Attack, while Modern Sonic is equipped with a Homing Attack and Sonic Boost.
Sega hasn't so far specified a release date other than "later in 2011," nor has the company revealed which other characters will be making an appearance in Sonic Generations. Series stalwarts Tails, Knuckles, and Dr. Robotnik would be fairly safe bets.
Mixing 2D and 3D sections worked well for Sonic Colors on the Wii, a 2010 game which went some way towards reinvigorating the series.
De Blob 2 also made use of both side-on and three-dimensional levels, and Sonic's great sparring partner Mario can bounce around 2D and 3D areas in Super Mario Galaxy 2.
Sonic Generations' official website: sonicthehedgehog.com/generations