A first-person shooter has become free on Steam

Origin of Decay is a post-apocalyptic zombie survival game now available for free on Steam.

After the explosion of the nuclear power plant, the radiation leaked and turned people into crazy killers. All reason and intelligence are gone, and only instinct remains to cry. Some of the lunatics began to eat people. In a ruined city alone, you get a radio from a virus lab that you overheard while living, and you leave the city to get a vaccine.