In the strategy game Monster Castle defense you need to place units in your castles to defend the princes from being attacked.Summon monsters and protect your queen from the evil human army. Place skeletons, demons, plants and other monsters on every floor and kill soldiers, priests, mages and other enemies. Defend the Monster Castle at all costs. Your mission in this retro defense game is to protect the sweet princess from an evil human army.  Try to destroy all waves of enemy units that approach each castle using various forces. Enjoy!