Wow! Claymation deserves the biggest applause. Very unique style. I personally would look into physics of jumps a little bit tho. But maybe it's just my preferences.
Ah yes the platforming seems to be the main complaint, I thought i follow the principles of good jumping and its to my liking, but i think thats just cause im use to it. are you able to identify what feels janky to it?
I may be wrong, but is 'movement-while-in-the-air-speed' always the same and after certain point character falls back with the same speed? It feels like you bump into something. There is a really good vid on the matter: