Ugh, this is what I get for not studying in my Spanish class. Someone please translate the interview video.
WITH PLEASURE, TRANSLATED LINE BY LINE! (If you find terms weird and/or repetitve blame the Japanese developer, not me):
In this year, 2011, it is Sonic's 20th Birthday. Sonic Generation's concept was essentially compress 20 years of history in a single game.
To accomplish that, what we did was mixing up the traditional Sonic, along with his traditinal platforming in 2D, and his characteristic gameplay with modern Sonic and all his very own features.
In our opinion, there are fans that enjoy 2D Sonic gaming, the action and platforming style, and others that prefer Sonic on 3D, as of 2010, we released Sonic 4 and Sonic Colors, Sonic 4 was oriented to the greatest classic-Sonic fans, while Colors was orientated towards the 3D loving fans.
What we have done in Sonic Generations is to create a game that is oriented to both "groups", we hope everyone enjoys this unique game and we can celebrate Sonic's 20th Birthday together.
Sonic Generation's design is an authentic syntesys of 20 years of Sonic, therefore, it is not focused in the character's classic elements, neither towards the new changes we've seen in the last year, instead, it tries to take in count every aspect seen in 20 years of Sonic history.
Today we had a demonstration of Green Hill Zone, wich is the very first level seen in the franchise, but troughout this year, we'll announce other levels for the game, and you'll notice they come out from everywhere.
It is not about new stuff or old stuff, but as I say, to "Embark it All", today we have announced we'd have 2 playable characters on Sonic Generations, wich are the "Classic" Sonic and the "Modern" Sonic but other characters from Sonic universe will also make their appearence, such as Tails, Knuckles, Shadow, etc. They will be an important element for the game but we've still got alot of surprises to show up.
The focus is to create an action game that is fun to play, wich can be attained the Classic way, but with old Sonic and new Sonic this time. For us to focus on that, there will be no cooperative or competitive gametype, but a pure action and platforming game for single player!