Place towers on a map and try to defend your borders from invading baddies.How to Play... Each enemy you kill earns gold which you can use to upgrade towers or build more structures. If a creep makes it through your defenses to the other side, you lose a life. Strike a balance between fast-firing towers and more powerful (but slower) units to keep your desktop free and clear. A good strategy is to funnel enemies around the screen in a twisted path, giving your towers more time to pelt them with weapons fire.