Sonic the Hedgehog: Awakening
Main game
Sonic the Hedgehog: Awakening is an unreleased game that was in development sometime between 2006 and 2009. The game's title was found on Pete Capella's resume, who was the voice actor of Silver the Hedgehog at the time and voiced the character in the game. It being on the resume means that it was seemingly far enough in development for voice work to be done. There's currently no other info about the game.