The game, which was teased last week, blends an intriguing mix of 2D and 3D Sonic gameplay — a first for the series.

As you'd expect, the narrative set-up is utter tripe, with Sonic stuck in weird "time holes". It's a perfect set-up for tossing Sonic backwards and forwards between his current day shenanigans and old-school adventures. Sonic will meet a bunch of his old buddies along the way, and we suspect there'll be more than a dash of fan-service.

Classic Sonic stages will be rebuilt from scratch in HD, and they'll be mixed up with more modern 3D environments. The game's due out in late 2011.

"Sonic Generations will certainly be a fitting celebration for Sonic's 20th Anniversary," insisted brand director David Corless.

"By having the classic 1991 Sonic that many fans know and love team up with his modern day incarnation, we are bringing back the nostalgia of the early days of Sonic and combining it with the innovation and stunning HD technology of the modern gaming era.

"Sonic Generations will bring to life the last twenty years of Sonic's universe in a truly unique and imaginative way."

It sounds intriguing. We can't wait for some footage better detailing the game's mix of dimensions. If the 2D sections play like Sonic CD, and the 3D sections play like Sonic Colors, this could be massive.