Genocide City Zone
From Sonic Retro
Genocide City Zone is an empty level found in the Sonic the Hedgehog 2 Simon Wai prototype. Chemical Plant Zone 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.
Tom Payne, the zone artist in charge of this level, stated that it was dropped before it was even started. Instead, he worked on the third act of Metropolis. In the Sonic Jam strategy guide Yuji Naka stated basically that the third act of Metropolis Zone used the layout meant for Genocide City and that it was meant to be a single act. Here is the quote in full:
| “ | Act 3 (of Metropolis Zone) was going to be a different Zone that would only appear once (one act)... We had already finished the map, and it would have been a shame to waste it, so this is what we went with. | „ |
Cyber City
On Nov 26, 2005 ICEknight 
released concept art of Genocide City Zone that indicated its early working name as Cyber City Zone. Due to the discovery of this concept art a theory that this magazine clip referenced the boss of Genocide City seems unlikely. The level is mechanically-themed, and bears a superficial resemblance to Chemical Plant Zone and Metropolis Zone.
| Sonic the Hedgehog 2 (16-bit) |
|---|
| Main Article (S2K) | Enemies | Bosses | Magazine Articles | Game Development | Game Secrets | Bugs | SCHG | OSV | Cheat Codes (S2K) |
| Levels in Sonic the Hedgehog 2 (16-bit) |
| Emerald Hill Zone | Chemical Plant Zone | Aquatic Ruin Zone | Casino Night Zone | Hill Top Zone | Mystic Cave Zone | Oil Ocean Zone | Metropolis Zone | Sky Chase Zone | Wing Fortress Zone | Death Egg Zone | Special Stage |
| Scrapped Levels in Sonic the Hedgehog 2 (16-bit) |
| Dust Hill Zone | Genocide City/Cyber City Zone | Hidden Palace Zone | Rock Zone | Wood Zone | Winter level |
