Classic sonic and modern sonic are separate universes.

[Ace]

It's known that since sonic generations that there are two different universes. One with the Sonic we know now, and one we all knew and fell in love with then. How do you feel about this explanation? (Personally, I no longer associate myself with the newer sonic crap, so having a universe in which none of that exists pleases me... Somewhat.)

(I've yet to try those sonic mania games, but I like how it looks like the Sonic I knew before everything else that came after & Knuckles.)

 

[Leaandro15]

Yea these universes are confusing and extra honestly it's just a game they'll still be playable and the "Universes" is just extra so people could see a change in the games and so there can be different plots and stuff as more games come out there are newer plots to games and there are new games because if no new games came out it would be boring just like it would be boring if the plot was the same for every new game that came out so yea just ignore these "Universes" and enjoy the game @Ace

 

[18]

That's like saying 2D and 3D Mario are different universes

 

[Ace]

@Spinnerweb But Sonic "literally" has two separate dimensions. (Something about the plot in generations from what I've heard.) As far as Mario goes, I think the only separate dimension from that is the paper Mario world.