Genocide City Zone

Cyber City Zone, originally known as Genocide City Zone, is a scrapped level from Sonic 2. It would have been a mechanical-themed level in tune with Metropolis Zone, albeit with a more futuristic appearance. Like many zones set to appear in Sonic 2, it was scrapped from the final release of the game, and the general idea of the level was reused for the third act of Metropolis Zone.

Contents
Cyber City Zone was set to be a futuristic mechanical level, with fans being the prominent gimmick of the level. The fans were likely intended to blow Sonic away much like they do in Wing Fortress Zone. As well as these fans, other level gimmicks include girders to run across, green elevators to take a ride in and conveyor belts to outspeed.

Remnants
Genocide City Zone appears within the early prototypes of Sonic 2, specifically the Simon Wai prototype and the August 21st 1992 prototype. However unlike Hidden Palace Zone or Wood Zone, Genocide City Zone is merely a string in the level select. The level itself is empty, comprised of a single repeating tile from Emerald Hill Zone and the background music of Chemical Plant Zone. This is because it was scrapped during early implementation, meaning that it never saw the light of day.

Digitized graphics intended for Cyber City Zone were later reused in The Machine, the third level of Sonic Spinball.