Sonic 2 Plotline - As Told By Manuals

Along the way of one of his impulsive adventures, Sonic suddenly discovered the island.
It was a small island, with pleasant green fields of grass spread throughout it.
"All right, it's time to take a little break." he said.
Drawing an arc of white exhaust,
Sonic slid his favorite plane, the Tornado, down toward the island's silhouette
…and almost as if it were following him,
a shiny little figure came down and suspiciously disappeared on the other side of the island.

--The Legend of West Side Island--

They say that a very long time ago,
the people of this island used mysterious stones to advance their civilization,
and they achieved great prosperity.

However, when those people people tried to use the stones in the wrong way,
their prosperity vanished overnight.
After that, they say that the gods sealed the stones away somewhere on the island.

One day, not long after Sonic had been on the island,
Sonic noticed something tagging along to his rear.
He turned around to see a little fox.
When the fox realized he had been seen,
he scurried into the shadows under the palm trees.
But when Sonic turned and ran off,
the fox followed behind him as fast as he could.
After a while, Sonic said, "Well, he can do whatever he wants."
And left it at that, not taking particular interest in whatever it was the fox was doing.

"Miles Prower" was the fox's name.
Miles actually had two tails, which is why the animals on the island all called him "Tails".
They teased him a lot because of those two tails.
But when he saw Sonic come to the island, he changed.
"I want to be cool, too!" he resolved.
After that, he started tagging along behind Sonic for all hours of the day.

Then came that one early afternoon.
Miles found a beautiful aeroplane down at the beach.
Miles loved all sorts of machines and vehicles,
and he practically tripped over himself running towards the plane.

That slim fuselage, and those wings that could cut like a knife!
Fascinated by this beautiful craft, Miles ran around to see the other side,
and there he stopped dead in his tracks.
Sonic was taking a nap under the wing.
Miles turned right around and went back to the other side of the plane,
and then it happened…
A flash shown off in the woods.

Then came an enormous explosion, and up rose a pillar of fire after it.
Shards of rock and pieces of tree came showering down from the sky.
Miles, narrowly escaping being blown away by crawling under the plane, opened his eyes.
Reflected in them was the the red of the burning forest,
and robots digging at the ground as though they were looking for something.
Miles couldn't figure out what was happening.

The explosions continued ceaselessly, and the island was blanketed in flames.
Miles was at a loss as he looked on,
but then he felt the presence of someone standing next to him.
He looked over, and there was Sonic glaring at the burnt up forest.
"Eggman, you bastard!" mumbled Sonic as he kicked up some sand and ran off into the forest.
Something had started, something truly incredible.
This was the hunch Miles had as he reflexively took off in the same direction as Sonic.

"Uwa—Ha Ha Ha Ha!!"
From the forest echoed that all too familiar vulgar laugh.
It's him - the one and only Dr. Eggman.

"I've found it at last! The place where the Chaos Emeralds sleep!
Following Sonic worked out perfectly!
Now I should be able to finish my ultimate weapon: The Death Egg!
I"ll be waiting for you, Sonic!
This time, my friend, this time I will beat you, and all the Emeralds will be mine!
Then I shall be the conqueror of the entire world! Gya— Ha Ha Ha Ha!"

The stage is set. Now it's time for you to bring the curtain to a close on this adventure once and for all!

Sonic 2 Dev - Revised Level Order

With more development materials released by Hirokazu Yasuhara,
the planning of Sonic has become more clear.
Not perfectly clear yet, but with all the maps accounted for,
and the full timeline sheet, along with more sketches,
I have pieced together a revised zone order:


Present:
1 Emerald Hill グリーン
2 Ocean Wind オーシャン
3 Secret Forest/Woods ウッド
4 Sandy Shower サンド
5 Metropolis メトロポリス


Middle Ages:
6 Tropical Sun トロピカルサン
7 Blue Ocean ブルーオーシャン
8 Mountain Madness?


Ruined Present:
9 Rock World ロック
10 Oil Ocean オイル
11 Dust Hill ダスト
12 Death Egg デスエッグ


Ancient:
13 Hill Top ヒルトップ
14 Blue ブルー


Future:
15 Casino Night カジノ
16 Chemical Plant ケミカル
17 Genocide City ジェノサイド
18 Neo Death Egg ネオデスエッグ
19 Space 宇宙


There are discrepancies between the timeline sheet and the maps.
With emphasis on the timeline sheet, the maps paint a different picture.
The maps show more zones in an era than the sheet says exist.
This could mean that the zone labels don't neccessarily reflect level order.
For instance, with Hill Top labelled in the Middle ages and Ancient maps,
they may have been labelled to highlight where the region had moved to.
The same could be said for Rock World Zone, with its region existing across eras,
but only being a playable zone, as Rock World, in the Ruined Present.

The middle ages were difficult to place, but Blue Lake seemed to fit,
as did the recently unveiled Fortress level in a Hill Top setting (Madness Mt.)

Sonic 1 Plotline - As Told By Manuals

The evil mad scientist Dr. Eggman is up to his old nasty tricks again!
"Sonic, that annoying, impertinent hedgehog.
Thanks to him, my great plans are always laid to waste!
Oh, but this time, I'm going to snuff him out with the power of science!
Ha ha ha ha ha…"

(from 8bit Sonic 1)

South Island is a treasure trove of gems and ancient ruins.
They say that it's the island where the mystical Chaos Emeralds lie.
The Chaos Emeralds are a super-material that give energy to all living beings.
When applied to scientific purposes, they can be used for nuclear and laser based weaponry.
However, nobody knows exactly how to get ahold of these emeralds.
Although, they do say that the reason why South Island is always moving
is because the emeralds are somewhere inside the island's hazy depths.


One day, crisis visited upon the island.
And who showed up with it but Dr. Eggman and his cronies!
"I'll find those emeralds even if I have to dig up the entire island to do it!"
Eggman set up a fort in one corner of the island, and went about carrying out his plan.


"Eggman, you still haven't had enough?"
Sonic hurried as soon as he heard the news
Eggman never seemed to leave him alone, even though Sonic had beaten him every time so far.
It seemed like Eggman considered Sonic his sworn enemy, but he was never any match for Sonic.

(from SegaSonic the Arcade)

However, this time something is amiss.
"Have you seen it, Sonic? This time is going to be different!
For this time, I've turned all the animals on the island into robots!"
"E, Everybody!?"
"All of them go about in accordance to my orders.
In other words, Sonic, everyone on the island is your enemy!
Gya— Ha ha ha ha ha ha, *cough* *hack* ahem,
This time, the world really will be all mine!"
This is terrible! Hurry! Sonic the Hedgehog - everyone is waiting for your help!

Sonic - Classic Timeline

Sonic the Hedgehog may have been the first game released,
but it was not the first in the series' chronology.
This was even made evident in the Japanese manual.
Sonic was noted to have quarreled with Eggman many times before.

Eggman with dialogue from the Sonic 1 manual:
(Artwork from Mania because I like it)

Chronological order of classic-era games:
SegaSonic the Hedgehog
Sonic CD*
Sonic the Hedgehog
Sonic the Hedgehog 2
Sonic the Hedgehog 3
Sonic & Knuckles
Chaotix
Sonic 3D Blast

(*Sonic CD can be at several times)

Breakdown of events:
An unseen first encounter between Sonic and Eggman
Sonic and co's escape from Eggman's prison island (SegaSonic)
Eggman's rapid mechanization of the Litte Planet (Sonic CD)
Sonic's defeat of Metal Sonic and Eggman's escape (Sonic CD)
Sonic's defense against the mechanization of South Island (Sonic 1)
Eggman's commencement of research on West Side Island (Sonic 2)
Sonic's disruption of Eggman's activities on/above West Side Island (Sonic 2)
Death Egg's descent onto Angel Island (Sonic 2/3)
Knuckles' collection of the Chaos Emeralds from Sonic (Sonic 3)
Sonic's failure to halt reconstruction of the Death Egg (Sonic 3)
Sonic's passage through Hidden Palace with Chaos Emeralds* (Sonic & Knuckles)
Sonic's defeat of Mecha Sonic in Sky Sanctuary (Sonic & Knuckles)
Super Sonic's defeat of Eggman over Angel Island (Sonic & Knuckles)

Eggrobo's awakening and pursuit of Eggman's busted plans (Sonic 3 & Knuckles)
Knuckles' destruction of Hyper Mecha Sonic in Sky Sanctuary (Sonic & Knuckles)
Mighty's arrival on the recently unveiled Mysterous Island (Chaotix)
Eggman's rapid construction on the unveiled Mysterious Island (Chaotix)
Espio and co's retreat to the Mysterious Island and capture (Chaotix)
Knuckles' arrival and rescue of Espio on the Mysterious Island (Chaotix)
Chaotix' defeat of Eggman and Metal Sonic Kai (Chaotix)
Eggman's retreat to Flickie's Island (Sonic 3D Blast)
Sonic's squashing of Eggman's research on Flickie's Island (Sonic 3D Blast)

(*Defeating Eggman as Hyper Sonic cancels out Knuckles' story)

Sonic 3K Development: Mushroom Hill and Sandopolis

Sonic 3 was developed in tandem with what became Sonic & Knuckles.
The original plan was to feature all content from Sonic & Knuckles in Sonic 3.
Ultimately, the content was divided between the two games.
As a result, zones were shuffled around; the most notable being Flying Battery.

Here is a map of Angel Island from Sonic 3K:

In this original configuration the zone order was as follows:
Angel Island
Hydrocity
Marble Garden
Carnival Night
Flying Battery
Ice Cap
Launch Base
Mushroom Hill
Sandopolis
Lava Reef
Hidden Palace
Sky Sanctuary
Death Egg

Sonic was to have launched up to Flying Battery from Carnival Night.
Then jump down from Flying Battery and surf down to Ice Cap on a door.
Launch Base always preceded Mushroom Hill.
With Flying Battery between Carnival Night and Ice Cap,
Sandopolis directly follows Mushroom Hill.

The shift in landscape there may seem odd, but I assure you it isn't!
Mushroom forests, acting as an oasis, have appeared within deserts before.
One prime example would be in Dragon Ball.
Emperor Pilaf's castle is situated in a desert that features sections full of fungus.
It should be noted that elements from Dragon Ball inspired elements of Sonic.
Perhaps most notably in the Super Sonic transformation, particularly in Sonic 2.

Also of note is that Mushroom Hill was once named Mushroom Valley.
Valley was likely changed to Hill when it became the starting zone for S&K.