Seems fun and solid. Though I hope you change it so that it auto starts a new fight. Unless I'm missing something, there is nothing to do prior to a battle. So adding the extra mouse click is just not needed and becomes tedious.
It does seem to be solid, and genuinely I like the pacing of the game. Some devs would make the monsters take 5 seconds to spawn. You didn't and its very appreciated.
I notice that once you clear a floor, it auto starts the fight. But again, it should just be auto regardless imo.