Your mission in this tactical tower defense game is to defend the final borderline against bloodthirsty monsters. Strategically place your turrets and upgrade them wisely to eliminate all enemy units and keep the area secured. You have two kinds of resources - money and energy. Protect the civil area where the energy is produced. Any intruding monster stops energy production temporarily. Use YOUR MOUSE to click on any available tile then select a tower to build. Click on an existing tower to upgrade, change or demolish it. Good luck!