Hi! First of all, big thanks for that time killer, it is really addictive! And useful indeed (to train attention, logic and ability to make decisions fast). So, OK, here are some suggestions: if it's possible, add the ability to place some simple navigation signs or different marks on the shafts (signs like left or right arrows and marks like green square, red dot and yellow triangle, for example). Because, the deeper the mine, the harder to navigate in the hell of ladders and gangways, so gamer needs to switch to the map and back to the field much and much often. If not signs or marks, then the ability to colour the ladders (like white is the defailt, and red, green and blue are optional) - that'll be good too. The Robot places one ladder unit, then you can hit G for green, R for red and B for blue on the keyboard to paint that ladder unit. That can make the navigation much easier, I guess.
And now the question: I've never been in such situation, but is it possible to blow up the diamond? (I mean, blow it up with the TNT accidentally).