Hey, sorry it took so long for me to come back with a new zone, but here we go...
1) Which way is up?!
2) All together now.
3) Woah! I have neons!
Is it Speed Stadium from Knuckles Chaotix?
1) Refers to the wierd gravity all Chaotix level had
2) There were some 7 (?) characters in the game.
3) All carnival levels have neons. ITS THE LAW!
Good guess, but not it. Next clue:
4) The heart of the problem.
It's from Sonic Heroes, isn't it?
Death Egg, Sonic & Knuckles?
Nope and nope. Here's another clue:
5) "Miles" ahead of the gang.
Battle Fortress from Tails' Adventures?
Nopers. Consult your awesome game libraries, peoplez.
K it's been a day of silence, so here's another:
6) Stop telling me what to do, Eggman!!
Is it Circus Park from Shadow?
Eggman and Tails are Shadow's helpers.
Neons + Carnival Level = The Law
Nope, try again.
Tails' section of Cannon's Core?
Not just Tails' sections, but close enough so...
Ding, ding, ding! We have a winner!
1) Which way is up?! (many gravity switches)
2) All together now. (you play as all characters from SA2 except Shadow during this level)
3) Woah! I have neons! (while walking around some areas, the characters look like they have neons underneath them similar to cars)
4) The heart of the problem. (core = heart)
5) "Miles" ahead of the gang. (Tails starts off the level)
6) Stop telling me what to do, Eggman!! (Eggman begins by giving Tails directions)
Your go, Koivo!
Again? Ok...
1) 10! 10! 10!
2) Ooooo.... 3D.
3) Watch out for that tree!!
White Jungle in Sonic Adventure 2.
That would've been my first guess, so...
Green Forest from Sonic Adventure 2
Odd... THAT was MY first guess! I'm not kidding.
I changed my mind for these reasons:
1. SA2 was Sonic's 10th anniversary game, You have 10 minutes to complete White Jungle, And I do believe it was Stage 10 for the Dark story.
2. SA2 was in 3D
3. George of the Jungle reference (Dang, I loved that show!) due to the fact that Shadow ends up swinging on a vine through a jungle.
Wow those answers DO fit the clues but its neither of those sorry.
Wow. The only other one I can think of is Lost Jungle in Sonic Heroes...
In the event that THAT isn't it, either, I'd say another clue is in order.
Good point! And its not that either.
4) Its not a jungle level.
Lol!! Sorry, I promise an easier clue next.
Well, I'm outta ideas...
It's been a while, so I claim this, if only to increase my "Name That" count!! 
1 - Too early to pop the champagne yet.
2 - More fun that a couple of barrels full of monkeys.
3 - Sub-Zero would be pleased.
Mwhahahaa! GO!
But I still want to know Koivo's...
I'm certainly not gonna stop you guessing that one, nor am I gonna stop Kovio form positng the answer, but ze rules are indeed ze rules.
Waitaminute... GyserHog, is yours Sonic 3's Ice Cap Zone?
Nope. It's not Ice Cap. ^^
Was I close?
That would be telling. 
EDIT: Meh. Like 'Name That Quote', I'm gonna throw this one. It was Toxic Caves, from Sonic Spinball.
1 - Too early to pop the champagne yet.
You have to pop corks throughout the level.
2 - More fun that a couple of barrels full of monkeys.
There is part of the level where you can proceed by busting barrels.
3 - Sub-Zero would be pleased.
The boss is a Scorpion.
Ooh, I'll take this one.
1). Deja vu?
2). It sounds hot.
3). You're better off praying.
ETA: Guess, people. =p
I'm gonna guess Death Egg from S3&K, based on the first clue alone.
Nope!
Volcano Vally... cuz... you know... it sounds hot
Nup.
4). Handheld
Hot Crater?
Nup.
Lava Powerhouse for Sonic Spinball GG/SMS
1). Deja vu?
Deja vu of its Mega Drive/Genesis counterpart
2). It sounds hot.
Lava.
3). You're better off praying.
Not sure.
4). Handheld
Yep.
Nope.
*revive*
1. Edgar Allen Poe
2. Who will you contact with a phone?
3. Time's run out...
