Your chopper crash-landed at an urban war zone. Use your machine gun to get through the hostile enemy soldiers while moving closer to the extraction point.
You're on a rescue mission. Get all your wounded soldiers out of the enemy territory. Just watch out for soldiers that have already transformed into zombies.
A Soviet soldier taking part in the Battle of Stalingrad in 1942. To purge the city from the invading fascists, you got rifle, grenades and you can call backup. Make use of the reinforcements at your disposal.
Nobody pays attention to a meteorite fall in the jungle and a few years later, military satellites discovered strange activity in the jungle. Your government sends elite commandos to find out what is going on and to try and clear up the situation..
