I've been wondering for a while why Classic Sonic is called "A sonic from another dimension" in Sonic Forces. Since there aren't any official confirmation on that matter, I tried really hard to think of a theory which would explain that. Before I begin, this is only a theory, so whenever SEGA/Sonic Team confirms it or not, it's still not considered a fact. Alright, so Classic Sonic...he's known as the past version of Sonic in Sonic Generations, and got the same traits from the classic series. We already know that time traveling is a typical thing in the whole franchise, and since the Storybook series is now canon, dimension-hopping is also a thing. In order to prove my theory, lets go back to Sonic CD. For those who played the game, you should know that there are 2 alternate endings: 1. Bad Ending - Little Planet leaves Never Lake, Robotnik succeeds and the planet is left under his rule, in a decaying, mechanized state. However, time resets, thus causing Little Planet to reappear at the lake. Sonic returns, determined to save the planet. 2. Good ending - Little Planet is returned to its rightful state and leaves Never Lake. No one really knows what directly happened after the Bad Ending, but I'm pretty sure that Little Planet was(and still) near Mobius since then, even if it wasn't seen from Mobius itself. Most fans know that in Sonic CD, you race against Metal Sonic in Stardust Speedway...in the Bad Future. While it's still possible to race against him in a Good Future, it was mostly known as a race in it's Bad side. And that still left me a question: In Sonic 4 Episode Metal, we see a broken Metal Sonic in Stardust Speedway....but why in the Bad Future? Let's get back to it later. Speaking of Sonic 4, there was something in that game which you couldn't perform in the previous classic games: Homing Attack. It's weird, because Classic Sonic never learned how to do that....or did he? That's how Sonic Generations gets into the picture. For those who played it, we saw Classic Sonic imitating Modern Sonic's homing attack(although he failed miserably), before he and Classic Tails return to their own time. Don't you think it's connected somehow? It also means that Sonic is stuck in a time paradox, growing up, meeting his past self, and leaving impressions for him so he'll use it later. Going back to Sonic 4, we already know that Robotnik planned from the beginning to create a new Death Egg, using Little Planet itself. But if it was a Good Future, it would be impossible. It wasn't specified from what reason Little Planet appears once a year for a whole month, but my best guess is that it's connected to the Time Stones. I mean, it would be weird for Little Planet to reappear at a different place rather than reappear once again in Never Lake like every year. Although our standard rules of time does NOT apply to Little Planet, It's still possible that the future can be changed permanently using the Time Stones as a time-travelling method. And if you all remember the Bad Ending of Sonic CD, Robotnik still held a time stone before he was defeated. It is hinted that when he used the Time Stones in Sonic 4 Episode 2 to control Little Planet, it was actually a backup plan if the previous Death Egg(referring to Sonic 3 & Knuckles) will be destroyed, which did happen thanks to Sonic and Tails. Now let's talk about Sonic Forces: While it's yet to be seen if Classic Sonic can do a homing attack or not, it was already confirmed he can perform a Drop Dash, his new move in Sonic Mania. The question is: Is it possible that he never learned the homing attack? So that means he never met Modern Sonic at all? That's why he is called "A Sonic from another dimension" ? If my speculations are right, Classic Sonic in Sonic Forces is NOT the same Classic Sonic in Sonic Generations. I mean, Sonic Mania is considered a sequel to Sonic 3 & Knuckles, then what about Sonic 4? Does that mean it never happened to begin with? The whole Sonic 4 event happened because Robotnik had a plan in mind, but in Sonic Mania, Robotnik sent his Hard-Boiled Heavies to reach the "mysterious powerful energy" signal first before Sonic and his friends. Why would he build a new team of robots if he could just find Metal Sonic in Little Planet and send him there? That's because he couldn't. He doesn't possess the Time Stones anymore, and reaching Never Lake would take too much time. My conclusion is: It's only because Sonic made a Good Future in Sonic CD which led him to a parallel timeline. Sonic Mania happened because of that, and all the games we know from Sonic Adventure till today will never happen. Eventually that Sonic(For now i'll call him Good Future Sonic) went to the destroyed city in Sonic Forces, located at one point in the canonical timeline, which for him can be suspected as unfamiliar. If my theory will be confirmed as true, then we can also conclude that Sonic Mania is a soft reboot to the series. While Bad Future Sonic will grow up to be the hedgehog we know today, Good Future Sonic just began his newest adventures. But thinking realistically, this theory is way too complicated for SEGA/Sonic Team to explain in a game for children, and yet I had the urge to connect the dots based on logic. So what do you think? Do you think i'm right or wrong? Let's discuss!