GTA: Royal Squad
Out of nowhere, armies of darkness began marching in on a castle. No one was prepared, so everyone can't do anything. But, soon strategist has been able to devise a plan. He would put archers and mages on top of towers to hit the incoming attacks before they can be close. The game is played with a mouse. You need to hire some mage and archers to defend your land. Summon some militia to defend when the enemies are closer. You can also set some trap and summon lightning to reduce the number of enemies. You can upgrade your men after every level.