Whao.. SO COOL!
Empty-Pen, you're right. It was most likely meant to be in Sonic 3, but was later used in Sonic & Knuckles. Actually, it IS in sonic 3. It's not used in any level, but it can be heard via Sound Test, like many other Sonic & Knuckles songs. Other than that, this song is a really good remix. You should try for a Sky Sanctuary/Dr. Robotnik's Mean Bean Machine End Credits remix.
i love this music also to the guy below me it's SUPPOSED TO repeat....
You nailed it. ;D (Also, at 0:38 it repeats. Why? Was there like a 'glitch'?
Too short! make it longer, get a 10!
Please contact me if you would like to use this in a project. We can discuss the details.