Wow that's a game I really liked !
It reminds me so much of the time I spent in pokemon 4G in the tunnel mining things and I loved that :3 The concept is pushed further by adding multiple layers and by using several tools to speed up the mining process but that may damage the gems if you use it wrongly. I really like the idea and the execution ! Though it took time to understand what the game was expecting from me (I always read the game page before playing and it didn't really help :s). When I understood what I had to do, it was plenty of fun and I really liked replaying the game until I finished it !
Well done !
