Since you're not really going to update this game, I should say something for your future games.

- if your game has something unique (for example dashing as in this game), you should make it the main point since platformer is extremely overfilled genre. in this game dashing only appears after 10 or so levels, player could quit before they get to those, it would be much better if it appeared in 2-4 level.
- controls should be intuitive, and 1/9 is totally not intuitive, space/shift would be much better.
- graphics are messed up, things' pixels are often different sizes, main pixel art point is that pixels should be the same size

that's pretty much it, i only focused on downsides, but if it's actually your first ever game and you made all the graphics yourself, it's quite good.