Board Thread:Speculation, Theories, and Rumors/@comment-4892653-20170317204901/@comment-679780-20170319214356

Ultrasonic9000 wrote: It has been hinted by Shun Nakamura that Sonic was doing something else while Eggman conquered the world. The question is: what could it have been that has kept Sonic out of the loop this much? Maybe... well, bit of a stretch. Maybe Lost Hex has its own time that flows faster than the rest of time. But even Eggman was in both Lost World and Runners so I doubt that.

Sonic's all about speed, especially when it's a race against time, such as stopping Eggman from pulling off something devastating. To drop the ball on letting Eggman have the occasional victory now and again is one thing, but the gameplay trailer is evident that Dr. Eggman has attacked that stage for quite a long time, perhaps a few months at least judging from the barricades and damages.

Maybe Nakamura was on about Classic Sonic doing something else preventing him from stopping Eggman, thus Modern Sonic saving the world.