Fight against zombies. They rise from their graves and head into the streets. Only a few cops have enough training to eliminate them. Everywhere are baricades to help prodect the city from enemies. That is the reason why shooting is more difficult, because you can not kill during you are walk. You have to calculate the correct angle for the cartridge to fly. And either you hit the zombies directly, or you shoot down an object that will finish your job. So save the whole mankind. Have fun.