Dude. It's like that because the original cue doesn't have any credit attached to it. It's just "Sega". Both Smash's music section and the True Blue album only list the original composer as "Sega". Try searching for Marble Garden, for example. You're not going to find it in that repertoire, despite the fact that we know who composed it. They're not making any royalties off it. Sega owns it lock, stock, and barrel. Even Retro's own article on Sonic 3's development says Jun has made it clear that he wasn't the composer, although I don't know what the source for that is. When Angel Island was included in the 10th Anniversary sound box, Jun Senoue was not one of the composers credited, while several others related to S3&K were.