After the leak of all videogaming leaks, initital silence from its creators and more than a smattering of rumour and speculation, SEGA has finally officially announced that the next platforming outing for its most famous hedgehog, Sonic Unleashed, is in development and will arrive before the year is out.

Sonic Unleashed, SEGA explains is built on the powerful new “Hedgehog Engine”, which introduces seamless 3D to classic 2D camera transitions, whilst also offering an expansive world with multiple paths to choose from. Said engine’s been in the works for some three years, and is something that SEGA hopes will re-define the Sonic experience for gaming veterans and newcomers alike…

…Well, given his poor performances in recent years, we hope so too.

Sonic Unleash’s storyline involves The Fastest Thing on Earth piecing the world back together after it has been destroyed by the evil Dr Eggman. Players will have to traverse a variety of action-packed stages across the Earth’s seven continents, on a mission to unleash Sonic’s abilities and save the world.

The title is said to make inventive use of daytime and night time mechanics, seeing Sonic whizz through levels in one instance, while partaking in combat-based challenges in the other. Sonic’s speed skills will be highlighted by four new modes (no details on these yet, unfortunately), whilst the all new combat, movement and functional abilities, SEGA promises, will offer depth and variety to the game.

“By combining rich and vibrant scenery with dynamic viewpoints Sonic Unleashed will provide an immersive 3D experience whilst keeping alive the 2D gameplay elements and fantastic worlds that Sonic fans know and love” commented Gary Knight, European Marketing Director for SEGA Europe. “In addition to this classic Sonic gaming experience, when darkness sets in Sonic Unleashed players will be able to experience a completely new way to play as Sonic… making this his most exciting adventure yet!”

Sonic Unleashed is planned for a worldwide release on the Microsoft Xbox 360 in late 2008.