Loved it, but got stuck on the third or fourth screen and just couldn’t seem to progress. But that’s a me issue, not a game issue!
The only thing I would suggest is some kind of visual indicator as to the strength of the jump (like the sprite crouching in stages or something), or make the “wind up” time longer, so it’s slightly easier to get a feel for how long to hold the jump key down.
An excellent entry, well done!