This is cool! The sprites are all detailed and smooth. And I was impressed that there was some variety in background color and tile sprites between levels.
I am not very good at platform games, but I was frustrated by the dash. It felt like I was constantly overshooting my target platform and falling to my death. It would be nice to have an option to cancel the dash halfway with a button press. It also seemed that I lost my ability to dash if I bumped my head mid-jump, which made some of the tightly stacked platforms extra challenging.
Other than the dash, the platforming feels pretty solid! There weren't any instances where I found myself falling through platforms or failing to understand the states and mechanics.
Nice work!