Slated to release on PlayStation 2, PlayStation 3, Xbox 360 and Wii, Unleashed is being developed by Sonic Team and is due out later this year.

Unleashed will mix the series' classic 2D run-and-jump gameplay with the 3D stylings of more recent Sonic titles. According to Sega, the game's "Hedgehog Engine" technology, which has been in development for three years, allows "seamless 3D to classic 2D camera transitions" and an "expansive world with multiple paths."

Going by the leaked assets and vague hints within today's announcements, it appears that Sonic will transform into a werewolf-like beast when night falls within the game.

"When darkness sets in Sonic Unleashed players will be able to experience a completely new way to play as Sonic," explained Sega Europe marketing director Gary Knight, "making this his most exciting adventure yet!”