This game is so cute and fun! I was giggling at the sound effects and the letters bouncing around. The game does crash if I don't delete connecting nodes first before deleting buildings - might be worth mentioning up in the description.
Thanks so much for the kind words! When you try deleting the buildings, try right-clicking away from the nodes, it seems that if you try to delete the buildings by right-clicking on nodes it will try to delete the connecting lines twice, which can cause the crash. Alternatively, you can delete the lines in advance by just scrubbing over them with the right mouse button held. Sorry for the inconvenience!