I enjoy idle games, and this has been a fun little diversion. However, I encountered an unfortunate bug in the late game. I reached Fortified Town 2 in my battles, and noticed that as I finished [5/5], the chest appeared but no skulls came out. I continued fighting through Fortified Town 3, thinking maybe I'd blinked or looked away and just not noticed, but this time as I finished [5/5] I watched carefully and sure enough, no skulls. I also noticed that up on the skulls button it said "+-299692..."
So I clicked the button and on doing so I could see that my Added after restart value was "+-299692921" In other words, the integer flipped to negative, and sure enough, it's now impossible to buy any bonuses or restart. Actually correction, it will let me sell off bonuses to decrease my "debt", and it looks like I could Apply & Restart those changes, but I have no desire to do so. So now my game is stuck, I had accumulated several million skulls that I was looking forward to applying to my Demons, but it looks like I can't do that unless some sort of bug fix is applied (in a way that will fix the save game, mind you).
Anyway, up until that point it was quite fun.