MORE. I would pay for a more developed version of this game. I love skill tree optimization, and this plugged right into my brain. It was fun discovering what each of the powers did and watching the character morph when they unlocked a new skill. Ghost dash FTW.
Very interesting idea having healing be an option for leveling up, so I always kept at least 1 level in my pocket in case of emergency. It would be great if there was a quick key for it, though, since it needs to be clicked quickly and scrolling across a large tree to click a small node is fiddly in the midst of combat.
Best record is Lv109, wave 27. One of my favorite games this jam.