1.) I think the dash feels good. I didn't realize it gave iframes (I probably should have), so I mainly used it to back up away from enemies quickly.
2.) The enemies feel decently easy as a one-on-one, but I imagine more than that would be difficult.
3.) I'd like to see a jump. I realize this means you'll likely be needing to add jump attacks, but it feels weird to me that the game mostly takes place on a one dimensional line. There's the one enemy that can jump, but since the player can't jump it acts more like an "invincibility state" than a jump, at least in terms of design. I totally get if you don't want to add something like that, but as I was playing I kept thinking "Man, I wish I could jump"