Just a mix of Act 2 and 3 of Sky Fortress from Sonic 4 Episode 2. I had this sitting around for a while now, but I decided today to do a little more fiddling with it and decided to throw it up here.

I actually really like Sky Fortress 2/3's music, and honestly wanted a shot at it, but I felt like they needed to be combined, even though they're similar, they do have unique parts to them. Though in the end this is more an Act 3 remix honestly.