Game crashed when I was at 55 crystals :(
Really good concept though and fantastic execution. There's something really satisfying about exhausting a vein of crystals and then whipping that entire branch of pylons across the map with all your units marching behind to reach another vein of crystals.
One bug I had was that there was this pylon making unresponsive miners, so I just had to make another pylon and make the miners from the new one.