The castle is under siege and as one of the soldiers, it is your duty to defend the land. Don't let anyone destroy the castle or at least destroy the tower, to which you are in. The arrow keeps on shooting to where you point your cursor. Each kills earns you money. You can use the money to upgrade your power after every level. You can also learn skill in due time. Aside from learning new skills, there will be other benefits that you can have like knights, vampire shot and many more. There are three modes in this game, but you need to finish the first mode before you can unlock a new one.