So far, the zombie apocalypse could have happened exactly 237 times. The streets could be flooded with hordes of nasty brain munchers. Human civilization could have collapsed and been forgotten. This did not happen thanks to the efforts of top secret units, which intervened every time and eliminated the problem before the situation got out of hand. This time you are sent to the inhospitable areas of the Rocky Mountains to investigate the disappearance of a seismological expedition. CAMPAIGN THAT CAN BE PLAYED SOLO OR WITH FRIENDS Slaughtering hordes of zombies is fun, but it's most fun when you do it with friends! Team up in online co-op or split-screen mode and give them a blast playing maps included in the story campaign and endless mode. FEND OFF HORDES OF ZOMBIES IN DYNAMIC BATTLES When there are a lot of enemies, you have to use your time and resources wisely. Barricades, explosives, heavy stationary machine guns, decoys and even artillery cannons - these are just some of the structures that will help you clear the underground of brain munchers. GATHER RESOURCES AND DISCOVER SECRETS The dungeons hide a lot of secrets - explore them, complete side objectives and acquire new pieces of equipment, knowledge and skills. Return to places you've already visited to unlock previously inaccessible areas and see what you can find! LEARN THE STORIES OF THE WORLD AND CHARACTERS Follow the trail of a lost seismological expedition, explore abandoned Cold War era bunkers and work your way deeper and deeper. Discover where zombies come from and why they roam the underground. Find notes, fragments of diaries and conversation records and learn the dark secrets of an underground civilization. DEVELOP YOUR CHARACTER'S SKILLS Each opponent you tear to pieces will allow you to grow stronger and hone your skills! Invest points in dozens of traits, become faster, more accurate and stronger. EARN AND UPGRADE EQUIPMENT AND COSMETIC ITEMS Every job is better when you have the right tools: rifles, shotguns, submachine guns, flamethrowers, grenades, landmines - something for everyone! Don't forget about appropriate clothing, a backpack and a hat - you need to look good while working.