Drink coffee.
Collect Coffee Beans from Coffee Plant -> use Coffee Beans on Campfire -> Coffee is created -> drink it
Thank you! I'm working on it at the moment :D in the next update the boss will get a more interesting behavior (probably some kind of AOE attack) and an experimental first NPC quest system is on the way.
Also: this is currently the prototype state. A proper DEMO will be published as a separate Itch game after the prototype state is over.