Sonic Unleashed is being developed by Sonic Team, and will be released late this year for Xbox 360, Wii, PlayStation 3 and PlayStation 2. It features "classic Sonic 2D gameplay" rendered by the all-new Hedgehog engine, which apparently excels at seamless 3D to 2D camera transitions. Observe them in the official, non-leaked, absolutely watertight video.
The engine's been under development for three years, with the intention of blending a next-generation look with classic Sonic gameplay mechanics. Purists rejoice. We certainly are: it looks lovely.
It wouldn't be a Sonic game without a gimmick of some kind, however, and we're promised a "completely new way to play as Sonic" when darkness sets in - lending more than a little weight to the earlier claims that he would transform into a werewolf. Combat will play a much more important role - in the werewolf sections, we're betting - while Sonic's more traditional high-speed skills will be featured in four new modes.
The plot's pretty simple: Dr Eggman has broken the world apart, and Sonic must travel around the seven broken continents, sticking it back together with Chaos Emerald power.
It all sounds appealingly old-school. Consider us cautiously optimistic, and watch out for more details on Sonic Unleashed in the coming months.