Note: Since the other thread is over a month old, I had to create a new one.


Sonic Generations Information Thread
Consoles: PlayStation 3, Xbox 360, Nintendo 3DS
Developers: Sonic Team, Dimps (3DS Version)
Publisher: Sega
Genre: 2D/3D Platformer
Players: 1 (PS3/Xbox 360), 2 (3DS w/Multiplayer)
Release Date: November 22, 2011

Summary
Sonic Generations is a game currently in development by Sonic Team and Dimps to celebrate Sonic the Hedgehog's 20th Anniversary.

The game features both Modern Sonic from the modern era (games such as Sonic Adventure, Sonic the Hedgehog: Aka Sonic 06, Sonic Unleashed, Sonic Colors, etc.), and Classic Sonic from the classic era (games such as Sonic the Hedgehog 1-3 & Sonic & Knuckles, Sonic CD, Sonic Spinball, etc.).

To please both Modern and Classic fans, Sonic Team has combined both play-styles into one game. Modern Sonic will be voiced by Roger Craig Smith, and Classic Sonic will not have a voice actor (in respect to fans).

Plot
An unknown enemy has used a special power to erase time and space in Sonic's universe, which creates time holes and causes Modern Sonic to be sent back in time and encounter his former self (Classic Sonic). As a result, both Sonics team up to stop the new threat.
Other characters in the Sonic universe may appear in the story (such as Shadow, Tails, Knuckles, etc.), but have not been confirmed.

Characters
Classic Sonic & Modern Sonic

Dr. Robotnik/Dr. Eggman

No current images, but has been shown in-game on a signpost.

Tails (Non-playable)

Fang the Sniper (Cameo)

Bean the Dynamite (Cameo)

Bark the Polar Bear (Cameo)

Unknown (New enemy)

Omochao (City Escape)

Gameplay Details
Sonic Generations is both a 2D/3D Platformer, and features gameplay derived from the classic era (traditional 2D platforming), and the modern era gameplay derived from games such as Sonic Unleashed and Sonic Colors.
The 3DS version has gameplay akin to Sonic Rush, which is 2D Platform, but different from the traditional gameplay in the classic era.

Stages
Classic Era:

~ Green Hill Zone
~ Casino Night Zone (3DS Exclusive)
~ Chemical Plant Zone
~ Sky Sanctuary Zone

Dreamcast Era

~ City Escape
~ Speed Highway

Modern Era:

~ Spagonia
~ Crisis City
~ Planet Wisp

Special Stages

~ 3DS Exclusive, but there will be Chaos Emeralds on the consoles, just a different way of getting them.

Credits
Sonic News Network:
Sonic Generations - Sonic News Network, the Sonic Wiki - Sonic heroes, villains, games, and more
IGN
Gamespot
Flickr


Notes
This guide is not yet finished, I still have to update it until release and add extra info, images, and videos until the game is released, it would be much appreciated if anyone could gather info I don't have so that I can add it in, thanks.