Pay-to-play has killed flash / casual gaming. This isn't a TD. There is almost no skill involved and it is just a grinding game that tries to annoy you into paying.
If I use Call to Arms and God's Hand to artificially increase my Tax Collection bonus above the "Coins Required for the Next Gem", I can get 10 gems at once because the counter does not reset. I have 2000 gems. You should probably fix that.
 "NGU IDLE"){kind=icon}
 "Medieval Cop"){kind=icon}
 "Idle Monster TD"){kind=icon}
 "Castle Clash"){kind=icon}
 "Realm Grinder"){kind=icon}