Any chance you could lower the overly excessive upgrade times? From reading other reviews I know I'm not the first person to mention this. That why is so much of the game stuck behind a ridiculously priced pay wall? Who do you think your average player is, bill Gates? Not once have I been attacked by another player which is a clear sign that there are very few active people on your game? Maybe try lowering or even better completely scrapping your prices and I'm sure you'll get more users.