You're a soldier of the special forces of your country. Your mission is defending your military base that has been recently attacked by the enemies. Take your weapon and shoot them until killing them.
Use the mouse to move and click to shoot. Destroy all your enemies to get points. Take the boxes that fall from planes, they give you ammunitions. Click on the guns below to use them whenever you want. Avoid shots or your energy will decrease and you'll lose. You have three lives.