Here is a field covered with square tiles. This is the place that you must guard in the Crystals And Monsters. Monsters will appear on the left and try to go through the entire field to the right exit. To prevent this, put on their way stone towers with colorful crystals at the top. These crystals are magical. Some will burn the enemy. Others will freeze, and still others will be showered with poisonous green gas. Your victory depends on the correct placement of the towers. Consider that your treasury is not rubber, money is enough only for a few buildings. To earn, you need to destroy the monsters.