Here's some new stuff, Cyber City Zone aka Genocide City.
A new video published by the Video Game History Foundation has unearthed some fascinating new information about the Mega Drive classic's development, alongside a new stage reveal and a reconstruction of a Zone once thought to be entirely lost.
The long and short of it is that, through some fantastic donations and insight from former SEGA Technical Institute developers and artists, the VGHF organization was able to document and archive a previously-unseen Winter variant of the well-documented "Sand Shower" (aka "Dust Hill Zone"). You can see an image of this below:
Now, we all know that part of Sonic 2's chaotic development involved time travel, before the concept was scrapped ahead of the game's final release. But what's interesting is the video explains that, in order to fit as many stages as that original idea would have needed (the video discusses, via concept documents, a 'future' South Island that included no less than THREE Death Eggs installed on the planet), the studio decided to recycle art assets to save on memory. As a result, the above screen you see here would have most likely have been intended as a past or future version of the canned Sand Shower Zone.
It also means that various stages that DID end up in the final version - including Chemical Plant and Hill Top Zone - were originally planned to be past/future or otherwise time-travelled "remixed" versions of other Zones in the game.
Using assets from a number of Sonic 2 prototype sources, combined with colour palettes and background work from Sonic Spinball's "The Machine" stage (a level which was confirmed in the video to be the recipient of a lot of Cyber City Zone's hand-me-down art) and existing stage design maps from Hirokazu Yasuhara, the above result you see is an experimental project that aims to re-imagine what one of the planned penultimate stages of Sonic 2
might have looked like.
All in all, it's a fantastic piece of game research and a cracking video - it's well worth the 20-minute watch, so we highly recommend you spend some time over lunch to view it and learn more about the never-ending mystery that is Sonic the Hedgehog 2.