I was bombarded with the Ads of this game in my other favourite game (Tower Defence). And it gave the Clash of Clans vibes. I never bothered to check this.
The biggest problem with such a game is that it's Free to Play, you at time, become a fodder to the guys who are spending on it. No chance of one beating the game or getting into decent levels unless they pay for it. Or go for an inhumane grind.