I see this is your first game published on Itch! Very good job!
You are now a game developer!
I appreciate sticking with the low risk goals of collecting leaves, and it was not at all punishing if the player fell down to either another platform or the ground.
You picked some good assets to use. (never underestimate the power of free assets for a game designer)
Of course some sound would have been really nice, and there are plenty of free things out there. If you have an interest in music composition, My favorite tool is Beep Box and for sound effects, the quickest to use for me is JFXR
I like trying out different genres (for better or worse), but If you are going to do more in the platforming area, I recommend you look up some additional platformer terminology and physics. It is a little counter-intuitive, because what players want for a good feeling platformer physics is not at all anything similar to real physics.
Adding in a jump buffer, Coyote time, and falling when the jump button is let go early would all do a great job in improving it. This YouTube video is a great analysis of one of the best platformers out there, Celeste: