Free to play, pay to have fun playing. Unless you pay a good amount of cash, it's not engaging. Goblin spawn rate is so slow, unless you pay. Goblin cannon upgrades too slowly, so upgrading your goblins takes forever. And I despise the ad delivery. Ads should never force you to the play store, but half of them do. And it takes three clicks to end any ad, making some ads last up to a minute. These shortcomings make the game much less fun each day.