Decent...but not that good. Planes with random drop will fly every few minutes, untill you buy that 15$ no adds option. Then they fly once in 15 or 20min. Every now and then all workers would collect resources needed, and then, for no reason, they would not start crafting. So you have to exit/reenter. And by that time, you have to collect all the resources again. So all in all, decent...but not that good. Map is too small etc...all that has been said already. And for 15$...rip off