I like the concept! Nice work. Graphics are really nice, who did the art?
Feedback: Without instructions, I am not sure what is going on. Even if it is unfinished, take some time to write out an explanation of what we are seeing.
Ideas: I think it would be cool to see the mines grow underground as your workers dig deeper. Another idea, certain folks will come to you with a problem for you to quickly solve. Simple as “Should I plant corn or tend to the mines?”