Climate change revives a virus buried under the permafrost. They spread and turned most of the inhabitants into undead.
Zombies are hungry, ferocious and wandering around. They attack and infect anyone on their way. To protect your family, you must kill zombies with your gun to avoid widespread humanitarian disaster. You have to use all means to prevent zombies from flooding into your city, using machine guns, grenades. Even shooting into cars, motorbikes, and oil tanks created big explosions of petrol bombs to kill zombies.

Strategy to survive each wave of zombies:

When zombies are far away, use machine guns.
When the zombie is a little close, use shotgun.
Surrounding by zombies using grenades.
When you see zombies walking around a car or a barrel, shoot that car or oil tank to create a big blast to kill all zombies.
Remember to buy more bullets and grenades for next scene.