New Sonic 2 development lore drop - Genocide/Cyber City palette and art!

That's what I've been thinking. While I cannot see a direct connection between Dust Hill and Madness Mountain, I'd totally buy the idea that concepts from both were reused in Mystic Cave.

 

I swear I remember reading Naka (or someone) changing the theme of the level after hearing a composition sent in. Wasn't the music composed based off of concept art? It went from a castle, to a haunted/spooky vibe castle, to then a mystic/spooky cave? I could also be pulling crap out of thin air as my memory seems to be junk but I'm hoping this triggers memories for someone else to expand upon.

 

Now that I think about it, how can we be sure it was an actual haunted house/castle? Naka said that it had the feel of a haunted house, not that it was one.

(quote taken from TCRF)

For all we know, it could’ve been something like Gimmick Mountain Zone from the 8-bit version, with it actually built into one of the island's mountains instead of being its own structure elsewhere on the island. That leads me, personally, to believe that it may have actually been unrelated to Dust Hill to some degree.

Besides, the team said they’d have created new levels through palette-swapping assets from other levels. Why would they go through the effort of drawing new assets for Dust Hill and turn it into something else? What was stopping them from going the route of Green/Emerald Hill and Hill Top and just making it another palette-swap?