Your mission in this shooting war game is to keep your base safe from the huge advancing army using your trusty sniper rifle, air strikes and artillery. With each wave the invading army gets stronger, spend your money on the right upgrades and try to survive the war. Spend your money earned on upgrades in the 'upgrades' menu. Use YOUR MOUSE to aim and shoot. Use 1-4 NUMBER KEYS to select special strikes. Use "U" KEY for upgrades. Good luck!