I really enjoyed this game!
Here are a few ideas for improvements:
1. Faster item selling: Dragging and dropping each item to the shop feels tedious. It would be great to have a quicker way to sell items—perhaps allowing Ctrl + right-click to select multiple items, or simply right-clicking an item in your inventory to automatically sell it when in town. (You might also consider adding an “Undo” button in case someone accidentally sells something they didn’t mean to.)
2. Compare new equipment: It would be helpful if, when hovering over an item in your inventory, the stats of your currently equipped item are also displayed. This would make it easier for players to quickly compare items.