I think you might be being held back by using Scratch. I know it's easy to get started in, but it makes getting into more advanced techniques more difficult. That said, getting something like this working in Scratch is impressive! I think you could improve your game with a few tweaks.
- Change the dash to be done over a short period of time such as 0.2 seconds instead of instant. Seeing the character move will make the game feel smoother and less disorienting after a dash.
- Fix responsiveness of the character controller. Sometimes when you switch directions your character won't change their facing for about 1/2 a second. The delay feels weird. It might just be a Scratch thing, but I'm not sure. Also the attack sometimes won't go off and there's not any feedback as to why.
I think you would benefit to pick up Unity or Godot. They are both free to get started with. The initial learning curve will be rough, but once you get over it many things will become much easier to implement. Keep up the good work.