Time Travel Possibilitys

Every Zone in Sonic 2 has 2 acts except Metropolis. Here`s an idea of how time travel might have worked in Sonic 2.

Since there are 2 acts in most of the zones, there is a possibility that act 1 would serve as the "past" while act 2 would serve as the the "future".

Example:

Hillside Havoc (Fake level name I made up)
Act 1:EHZ (Past)
Act 2:HTZ (Future)

Unlike in Sonic CD, You would probably be transported into the future of the level regardless of wether you passed a sign that said future or not.
Let`s take a look at the time travel possibilitys without the use of the "present"

(Past) Emerald Hill - (Future) Hill Top
Changes in the landscape probabaly turned the hill into a mountain (it would take thousands of years though)
Similairities:Almost everything

(Past) Aquatic Ruins - (Future) Chemical Plant
Maybe Chemical Plant was contructed over Aquatic Ruins.
Similairities:They`re the only 2 levels in the final that have water.

(Past) Winter Hill - (Future) Dust Hill
Ice Age ends and Global Warming begins.
Similairities:Opposites of each other I guess

(Past) Wood - (Future) Metropolis
Factory is constructed over forest.
Similairities:Tree holes resemble the transportation tubes.Not to mention the conveyer belts.

(Past) Hidden Palace - (Future) Mystic Cave
Man discovers the palace, man discovers that the palace contains emeralds, man tells his buddy, and a repeat of the Californa Gold Rush occures.
Similairities:Both levels are set in a cave

(Past) Casino Night -(Future) Genocide City
Robotnik buys the Casino Area and turns it into a city of mass destruction.
Similairities:This is merely just a guess

This is just my opinion though.What do you think?