I liked the branch and ant designs, and the sound (and was impressed that you had an options menu to adjust the sound levels down). If you had more time I would like to see the caterpillar body be less rigid and adapt more to the surface of the branch it's crawling on.
Gameplay wise I got stuck on a level where all I could do was go back and forth between two branches, collecting two leaves while avoiding one ant. I could have also stayed on the half of the level where there was no ant and just passively collected the ever spawning leaf if I wanted to take twice as long with zero risk of fall or ant attack. The progress to fill the metamorphosis bar seemed a little long to me, I would recommend that either be shortened or add some more dynamic challenges to the level if you keep the accumulation rate where it currently is.
First time I played I ran into a geometry seam and fell through a branch to my death.
The second time I played when I finally got my metamorphosis bar filled up I ended up inside a branch, and couldn't move anymore.