Like in every tower defense game you need to survive enemies attacking waves as much as possible. Monsters would attack continuously and you won’t have much time for thinking and planing where to put Towers. Try figure out which place is best to stop enemy attacks. Earn money by killing the evil creatures, that money use on upgrades of your towers. There is a several levels of upgrades and once you upgrade them to the max they will be capable to kill more enemies. If you need more money for the new Towers you can sell old to the store. Further in the game, enemy would become stronger and stronger. Beware of them. Only goal of this game is to last longest as you can, what do you think how much you will last?