I beat it \o/ I love the main character concept and the animations you've done so far are amazing. The mechanics too with being able to grow platforms and glide are sweet ideas! Also love the general theme about the tree and corruption, that boss was so unexpected It spooked me when I saw it :')
Obviously like you mentioned the game is unfinished so I don't really have any criticism that you wont already have thought of, I'd just like to second what miracle touched on with the jump, I think just being able to control xAxis movement in the air would make all the difference, rather than it being locked as soon as the player stops touching the floor, I had a few frustrating deaths from that :)