This would be a great time waster, but none of your ads work. Without fail, ads will play, but you can't "X" out of them to collect the rewards (you've got to restart the app); & so you effectively spend your time to watch ads & get monitized by the developers, but you do it for free. Unexceptable. When you fix this...you'll get five stars from me....Never mind, I just finished the game. Just that one stage to upgrade everything? Well there's nothing else to do, so....time to uninstall.