Pretty fun game. Slay the spire + rpg skill trees and overworld is a promising concept and I like direction you are going with a lot of the card/archetype designs. Placeholder art aside, the enemy sprites are good. You should add some screenshots to your page.
Some minor things:
My hp in the upper left kept rapidly flickering between 2 values.
I wish running made the character move faster rather then jump a set distance and then reset if landing in water.
i think walking away from the save crystals should close the menu automatically.
good early demo. looking forwards to more development on the mechanics.