As a celeste enjoyer, I really like this one. :D
My only real cause of frustration with this game is the lack of polish on the controls. Demanding the player to make very specific, well timed movements without movement features like coyote time, jump buffering, etc can make the experience kinda frustrating when they press a button a frame too late and end up having to restart the whole level again.
Also I don't see any reason why the dash stars shouldn't respawn like the disappearing platforms do. The player is already losing time when they miss a dash jump, you don't need to punish them further by also soft-locking them out of completing the level. :<
Apart from those minor issues, this is a solid game and I would definitely play a full version of it. :)