Cyber City Zone
From Sonic Retro
Cyber City Zone is a level intended to be in Sonic the Hedgehog 2 for the Sega Mega Drive, which was scrapped at an early stage or developed into a differently-named level. The only evidence pertaining to Cyber City is a piece of concept art (pictured). The level is mechanically-themed, and bears a superficial resemblance to Chemical Plant Zone and Metropolis Zone. It may also be related to the similarly scrapped Genocide City Zone.