I had a fun time playing, the art is very soulful and I can tell you made a great workflow for it. I never made enough to buy any gear, my potions seems ineffective and I died before I could complete the quest.
Some QOL would help, like not collecting keystrokes when clicked off the screen.
If you are planning on expanding this, maybe themed dungeons, and smaller quests? Like kill 10 rats, and there is a basement dungeon with lots of rats etc. etc. Also a map would be cool instead of just enemies. And maybe some events in the dungeon other then mobs? You could definitively add a lot.