Oh, I did like the sounds during combat - the integration of the FX and the sound brought the combat to life.
I like the fact that in mining the target tile heats up before it breaks, and this means that if you're trying to mine during an attack wave you can return to mining when there's a break in the enemies, and haven't lost all your progress - nice touch.
I searched for the shop, but never found it, and eventually died when I ran out of bullets.