Sonic Unleashed

From Sonic - Wiki on Neoseeker

Sonic Unleashed is the second newest game in the Sonic the Hedgehog series.

[edit] Story

It starts of as Sonic is on Eggman's Cruiser. Sonic fights Eggman as Super Sonic. Eggman captures Sonic and uses a ray to conduct the energy of the chaos emeralds. He splits the planet into 7 pieces. Sonic, is turned into the Werehog. He falls down to earth and meets 'Chip'. Sonic fights the Dark Gaia which was released from the planet's surface. Later in the game, you find out 'Chip' is actually Light Gaia and is supposed to fight off the Dark Gaia. Sonic and Light Gaia (Chip) travel to Eggmanland to rip it down and restore the last Chaos Emerald.