Скачать или смотреть Sonic 2 time travel title cards.

Green Hill Zone in Sonic 2 (Emerald Hill) is not the one from Sonic 1 (totems, checkerboard dirt and I guess flowers.) Yes Hidden Palace did had a different name, Chemical Plant also has it . (Both Secret Palace and Chemical Factory)
Wood Zone is Secret Jungle Zone. Yeah, Sonic 2 was originally taken place in South Island (before West Side Island was chosen to be the setting). It wouldn’t feature a time travel mechanic, it’s not like Sonic CD where you go past the sign thing in the game and go really fast then it takes you to somewhere. It wasn’t like that. But rather an adventure involving the island being in time periods. Such as present,ancient, ruined present, future and also medieval era. Madness Mountain was shortened to Madness M.T Zone to not be squished. (Similar to Gimmick Mountain Zone from Sonic 2 SMS/GG). Yes M.T does mean Mountain for short.
I believe the sprites for Sonic it wouldn’t been just been copy and paste sprites from Sonic 1 but a different color palette (as seen in TCRF and Tom Payne’s sprite work with scrapped badniks with him) instead of the ones used in the Nick Arcade/ Simon Wai Prototype Sprites we got from both.