A really good game with cool mechanic. Enjoyed it.
One of the issues was that when you try to place coins inside rocks, they bug out a little bit.
Also, I didn't really get the theme. The name of the game has dragons in it, but... there are no dragons in the game. Would be cool if there was more explanation of the story.
Otherwise, though short, a really cool game. I think it could be expanded and become a really great game!