Playing with the prompt: WASD: move the mouse aiming and shooting E: Switch weapons Shif: turret built into the interface, and then click Return of teaching the game of the hollow circle customs are going to fly to a destination, and some clearance is going to fly all over the all destinations, really boring. Some customs can not let you shoot, really abnormal. Games begin, we will ask you are not a green hand, the proposed election No, Customs will be able to skip teaching. After clearance of the project can choose to upgrade.