From Sonic Retro
Aerobase Zone is the sixth level from Sonic Pocket Adventure. The level theme and graphics are obviously based off of those from Sonic 2's Wing Fortress Zone, as the level takes place on a skybound air base. All badniks are from Sky Chase Zone as well, and it is a one level act. However, this act is twice the size of normal levels. Mecha Sonic serves as the boss. The music is from the first act of Death Egg Zone in Sonic & Knuckles.