Genocide City Zone
From Sonic Retro
An empty level in the Sonic 2 Beta ROM. No music plays, and Sonic and Tails fall to their death at the bottom of the stage. The only objects that this level has in debug mode are the two default objects, a ring and a teleport monitor. Many theories have been advanced concerning what this zone would have been like. There is not enough proof to prove or disprove any of them.