The game is cancelled, but the soundtrack is not
Sonic 2 HD is one of the biggest projects the Sonic community has attempted. After lots of controversy, the game was officially cancelled, but not everything about it has been lost.
Tee Lopes, the man behind the game’s soundtrack, has uploaded to his Youtube channel some of the tracks that were going to be used in the game, and he promises to upload the soundtrack in its entirely. For now, you can listen to some of his awesome renditions of Masato Nakamura’s tunes.
You can listen to them on YouTube, but here is a bit of what you can find there.