this is so cute and wonderfully done! I love the art, the cute sound effects, the background audio, the uplifting dialogue. I love how the colors get richer and richer as you go, and I love how you integrated collecting the hearts into the platforming itself!! Also I'm pretty sure you implemented coyote timer, and actually in some segments it is necessary for progression. Very well polished!
Indeed as the others said there are some blind falls sometimes but it didn't bother me much. I think the platforming was challenging in a good way and done really well as I mentioned above. I didn't skip any of the levels hehe. If I may give more feedback, the pads didn't always play the correct animation (jump would still work well), like the picture below is the first time I saw the animation. I was playing in browser so maybe that's why. 
The spike hitbox could be a tinyy bit more forgiving in some segments where you have to land between spikes.
I was very sad when I reached the end :( I wanted more. I honestly think the platforming was near perfect in this game. Reminded me a lot of Celeste in a good way. Keep up the amazing work!