Don't play this, even if you see that reward and it's tempting = =

Even if you have a lot of time and are willing to watch ads or follow other people's ad-blocking methods, later on, you'll find yourself getting one or even zero gems for no reason. There's nowhere to complain about this game, you can only give it a one-star rating. It's a complete half-finished game. Mobile mission games are just too terrible :/