It's essentially a corporately funded romhack made by the most autistic and skilled fan they could find. His others are better than the majority of official games Sega has released. I see no reason to think this won't be good.
Plus, everyone has been bitching at Sega for over 10 years for trying new things. So now they're finally doing Sonic 4 for real this time.
I'll take you at your word. You're still cherrypicking and then getting mad that a game doesn't even kill you for fucking up, but rather tells you to slow down. And still, as you've said, you can get around it very easily if you know it's there, or if you just aren't going fast as fuck. It's not like Sonic only has two speeds. You gradually accelerate, and you're acting like every player will be as going as fast as you were when you reached that point. I'm not sure where exactly it is in the game, but there are also many points where when you go fast, the game is set up in a way so you specifically don't hit things to stop you as long as you keep playing well. Such as sections where if you're going at a particular high speed you'll bounce off a bunch of enemies in a row. The point is, you're bitching about a very specific scenario you set up, and it's not even inherently a bad one. If you're gonna do that, you might as well use Super Peel-Out right in front of a wall and then complain that you hit it.
No, just around physics. Learn to use your momentum and you can get through faster and get to other places. The level design doesn't go against this, it just actually provides a challenge, so you actually earn your momentum rather than having it handed to you, like in Modern Sonic. You have moves like the Spindash or Super Peel Out, but if you don't use them well, you'll get fucked, because games from the early '90s were actually about challenge, and not just about handing you rewards for holding forward, as you seem to want.
It's not that the best games moved away from it, it's that Sonic CD in particular is a spinoff for an unpopular add-on, and thus the main series followed a different path. If you don't like Sonic CD, fine, but the depth it adds when it encourages you to look for Eggman's machines or the Metal Sonic Holograms has an appeal. Some people actually like learning the levels and looking for secrets. You're bitching about the levels not being made to go fast, but this is the game that has things that encourage you to go slow as well. You get different things for playing in different ways. It's also not a game where you're intended to see everything in one go.
All your complaints are about you finding it too hard to go fast.
Good for you. Too bad you're too much of a pleb to go fast and see the rest of the game.
You're complaining about the game not holding your hand and actually asking you to get good to see extra content. Maybe you're just confused because it will let you see the credits relatively easily, but if you want to see all the actual content, get good. Sonic CD has many more secrets than the rest of the series. That's what makes it fun.