I can see that Marble Garden, Carnival Night, Ice Cap and Launch Base are missing. That's not to mention competition levels such as Balloon Park and Endless Mine. Carnival Night, Ice Cap and Launch Base did have their tracks replaced for Sonic & Knuckles Collection, but not Marble Garden for some reason. Interesting. It could be just a coincidence in Pocket Adventure's case though. There wasn't an ice level in the game so of course there was no place for Ice Cap's music. That's not to say the music choices in the game made much sense to begin with. Desert Palace for Gigantic Angel? Sky Sanctuary for Chaotic Space? Well okay.