A portion of a NowGamer interview with Sonic Team's producer Takashi Iisuka...

NG: Following on from those 16-bit titles, Sonic went through many changes, the biggest being the switch to 3D. When making the original Sonic Adventure, just how difficult was it to take the action from 2D and 3D, and were you ever concerned that it might not work?

TI: Before we started the Sonic Adventure project, there were several development teams in SEGA who have tried 3D Sonic, like the quarter-view “Sonic 3D”, and projects which were turned down.

Turning Sonic into 3D wasn't that difficult. When we started “Sonic Adventure”, our goal was to come up with a 3D game which had the same feel as 2D Sonic game – comfortably speeding through the field by holding down the directional pad – which involved a lot trial and error.

I also remember recreating stage models. When we were able to have Sonic run through the loop for the first time in Speed Highway, everyone thought, “we now have Sonic in 3D”.

NG: What challenges do you face when creating new Sonic games when the fans who helped the franchise succeed many years ago demand 2D gaming, while younger fans want 3D? Is it as simple as just giving them both options in Generations?

TI: 2D action and 3D action are completely different genres, so I think it’s difficult to please both fans in one game. For this reason, we have released 2D-type Sonic 4: Episode 1 and the 3D type Sonic Colours last year. We will keep working to create games which both fans will be satisfied with.