Everything works great, there's a ton of polish in everything, and the game is sincerely just fun. I love this one. Actually spent the time playing through until I'd unlocked everything.
Stronger root was the least necessary upgrade, I found — it would have been nice for that to come into play more.
I also was a little disappointed that I got stuck at the midway point for most of the game, but at some point I reached some kind of breaking point and afterwards was able to make it all the way to the end without any trouble, so I didn't really get that sort of "ugh this section is rough" about any of the latter half.
Also, due to the speed upgrade in particular, and the fact that the root doesn't slide along objects towards your mouse, once you're very upgraded your only real threat is your ability to avoid obstacles. So the kind of game it was really changed at that point.
Anyway, I had a lot to say specifically because I had such a blast with this game. I'm sure any of the stuff I brought up would be the kind of thing refined from development happening over a longer period of time, haha. For the time you had, what is here is absolutely flawless. Thanks for the fun!