This is a lot of fun! Great work on the design!
I did hit a bug though.. not sure how to repro it either.
eventually I moved some little dudes away from a crystal but the the crystal still said that some of them were there when they weren't, and then I couldn't put anyone on that crystal.. later I made and upgraded a few more crystals but when I tried to put the little dudes on those new crystals they wouldn't be assigned. like I could still click on stuff and the little dudes followed me but they wouldn't let me assign them to anything halting the game completely.. was having a bunch of fun up to that point.
Though I will say that when I was on the road to 1Mil things got pretty choppy. so that may have been the cause for the other bugs. I was playing on the web build, so maybe the exe is better about this
Hope this helps to find the issue!