Nice rogue game!
The art is charming and the idea of combining all stats into only one is really interesting.
Your boss is a bit hard to master and depends on a lot of the stats the player collected. It's easier with the gun for example.
I think you can go deeper with that concept: doors that require currency to skip a part of the level for example. You can play a lot with your players by letting them the possibility to gain time by taking risks with that currency system.
Good job by the way! :)