Responding in a bit more detail, to what you said on a stream.
2. Especially for you, I played Mario (https://www.retrogames.cz/play_005-NES.php?language=EN) once again and... wow, how slow controls in Mario also feel. But that's a very old game and not necessarily an all-good game design. Take a look at something more modern. For example, Celeste (which you absolutely should play if you like platformers):
Note how much momentum is involved in the game, but the controls themselves are very responsive: you press - you move.Or Rogue Legacy:
Same here - immediate moves.Yes, in real life you don't move immediately but game is not real life and the main goal is to be fun, not realistic.
Besides that, characters in your game actually move and turn slower than humans in real life. Try it:)
And I don't mean you need to remove smooth turning all-together - no. I like that it's smooth, I just suggest to decrease momentum influence.
4. I played the first level and I can say it's very hard. It requires players to do many pixel/frame-perfect jumps. Jump slightly more or slightly less and you are dead. Took around 15 minutes to complete seeing both sides. Can't imagine someone completing it as intended. Have you playtested it with someone?