Good stuff for a first jam!
There is no health bar for the boss, and i was generally quite confused at the start on how the game was played. I can spam the lightning attack but I do not seem to lose mana nor does the boss do an attack after that.
The indicator of him going into the second phase is quite nice, he smoking that sticky!
And a simple indicator of when the boss is hit would do miles for this game!
Animations are nice but the idle animation seems to be too fast, almost like spasming.