Use the arrow keys to solve the puzzle of the mines. Push the crystals into chests to clear them from the level, clear all gems and you will be able to progress to the next level.
I enjoyed making this game as it really felt like it has old school gameplay. I have originally made 10 levels for this game, but plan to make more. And yup, those are Zelda sprites that you see there, I chose to use these as they game me an immediate graphical theme for the game and are awesome example of classic sprite design. I have used them 200% larger.