Best M3 game yet from these developers! The only thing I don't care for is the mandatory cave minigame successes needed in order to exit a level. I found a workaround for that.
Make upgrading the quarry to a 1:1 conversion ratio your highest priority, and make upgrading the Alchemist and obtaining the enhanced wood and rock pieces your second highest priority. Then, when you get to a cave, figure out if you need to buy a pack of hints, and if so, go topside, convert wood and rock to gold, then come back and finish the cave. Do the hints in order, and don't make any moves on your own unless you're absolutely certain it will lead to successful completion.
The only other advice I have is to choose Normal mode. Although you don't run out of lantern light in Relaxed mode, the light you have to work with ends up at the same intensity as when it runs out in Normal mode, and believe me, it becomes next to impossible to move around.
All in all, great game! I haven't gotten all the way to level 25 yet, and am anxious to get to the real truth about "Grandpa".