Yes, I already knew the bug but couldn't figure out a solution for it. It has to do with the transition of the unit between two tiles. When the unit moves too quickly, it cannot dig through the dirt of the new tile. However, when you trigger the transition again by moving back and forth it should work again. I actually intended the buy button to only appear when you are close to the base but didn't test it very well - could be another bug haha Glad you enjoyed it still! :)