Game has serious issues with losing progress in upgrades. As an example I upgraded a building yesterday for 12000 coins. And it was completed. Today. My upgrade is gone as is my coin. Upgrading buildings sometime requires watching ads to get pieces. You can bet that if you don't play for a half hour or more after doing this you will lose the piece you watched an add for. Focus should be on fixing these issues not biweekly new downloads of contests that seem to corrupt the game.