Cool game, it was fun!
The soundtrack is gorgeous!! I like it a lot, even though for my personal taste, it contrasts too much with the game mood.
I couldn't appreciate the management aspect of the game. I always had much more gold than necessary. I found easy exploiting the gameplay creating secondary useless tunnels to waste tiles I didn't need in that moment, untill I got what I want to proceed in the right direction.
Overall, a solid entry! Good job!