Here's an excerpt from something I'm typing up that I can hopefully show to this thread when it's done. There's a lot more context to it then you probably think there is and I want to back all of this up.
>Many Sonic fangames I see, such as Sonic Utopia, try to do the same thing: take the physics and momentum-based gameplay from the 2D Genesis classics (and Mania) and translate them into 3D. They do this because it seems logical, and because the Sonic Adventure games already attempt to do this to a certain extent, and they enjoy those games.
>The problem I have with this setup is that it assumes that is the only way for Sonic to be able to translate to a 3D environment. Or that it is the best way. Neither Super Mario 64 nor Super Mario Odyssey attempt to recreate 2D Mario gameplay. When Mario did try to recreate it, with Super Mario 3D World, the results were less-than-impressive. Neither Mega Man, Ninja Gaiden, Castlevania, nor Prince of Persia tried to recreate their 2D adventures in their 3D outings. Those that did, such as Prince of Persia 3D, and Mega Man X7, fell completely flat. And this isn’t just because the developers were incompetent: they were trying to make a game be like something that it just wasn’t. A three-dimensional environment offers so much greater potential for gameplay than just having the ability to run in any direction you want. And you will notice that every example I just named is a platformer. Keep that in mind, and ask yourself if you would rather play the Green Hill Zone stage in Sonic Adventure 2, or Seaside Hill Modern in Sonic Generations. The “boost formula” of Sonic Unleashed came out of nowhere, and it showed that Sonic does not even need to focus on physics and momentum to create a great Sonic game that still feels like a Sonic game.
>What all those examples all have in common, especially with Mario, is that instead of recreating what their franchises were, they recreate what people remember them being. They take the most memorable elements of each one and expand on them. They cut down on gamey elements and immerse the player in what it feels like to be these characters. When you play Super Mario Odyssey, you feel like you ARE Mario. When you play Ninja Gaiden Black, you feel like you ARE Ryu. When you play Prince of Persia: The Sands of Time, you feel like you ARE the Prince.
>And that brings us to our main topic: how can we feel like Sonic? What is it like to actually be in Sonic’s shoes, with all his abilities, in his own universe? What would someone remember Sonic being, as a child, in 1991 for the very first time? It all points to one answer: speed.
>As a child, I never cared or thought about how the physics work in Sonic 1. I never cared about how the level design has so many different paths to take. I never cared about the platforming challenges across perilous pits. All of that is nice, and something Sonic should have at least to some degree, but every platformer has that today. Sonic is not special anymore when it comes to that. All I cared about back then was seeing something that, even today, isn’t like anything else in gaming: seeing a stage and its visuals blaze by you, to the point where Sonic could even outrun the camera. That’s the one aspect of Sonic that manages to stay relevant and unique among every platformer out there.
>So we gotta have speed. Demon speed. Speed’s what we need. We need greasy, fast SPEED!