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!
Finish all 10 races in the quickest time possible. Finishing 1st will be given an upgrade, 2nd place will allow you to proceed to the next level without upgrade. Finishing 3rd will have you restart the race and more time is added.