Most of the feedback I have simply involves polishing what is already there. Some things that you might want to work on initially would be enemy hit registration, and feedback. I found it difficult to judge whether or not I would be hit by a goblin. Perhaps adding a slight delay and some animation there would solve that. Also one suggestion, rather than a critique, I would add some visual feedback that appears on the player as they pick up more and more ore. Maybe visually showcase the bag filling up with ore?