Keep peace and order. You're a soldier that has only been delivered for this purpose on the boundary between two countries which have been fighting jointly because your grand grand dad can recall. They maintain peace together, but only thanks to brave individuals just like you. Hordes of enemies immediately attack the border daily. When they crossed you over, chaos would reign and riots will begin. Fight out of the trench, be fast and steer clear of shots. At precisely the exact same time, shot enemies on the edge. Would you stop all of the waves of all bounty hunters? Have fun.