Loaded with ads, gameplay is constantly interrupted. You have the option to pay to remove ads, but the ridiculous amount of ads for free-to-play players is really unprofessional. I don't think the developers understand the value of a good user experience, they apparently didn't want to put the time into making an app good enough to engage the player and give them incentive to buy upgrades. This type of app isn't hard to build, the game is nothing special. The developers just want $$. Rubbish.