Zombie Apocalypse

This story/plot was originally written for my first person shooter Zombie Apocalypse. I never finished the game but am thinking of finally making it. So here's it's story/plot.

Scientists were trying to develop bacteria that would stop them from dying, to make them immortal but something went wrong. The bacteria they were trying to evolve had turned into violent viruses. They entered the scientists,turning them violent,turning them into something that was dead and alive. Those violent beasts killed and destroyed whatever came into their way. Some people evacuated and some became the victims of the violent beasts. The survivors evacuated in an underground passage. Soon enough,the whole city became infested with the walking dead. Then, these beasts were named "Zombies". The survivors put everything they had against these zombies but soon many of them became one of them. A man, named (your name) rose as the other survivors did and fought in the front lines. Many of the survivors were infected with the virus and (your name) went out in the city, accompanied by his allies, to retrieve some anti-biotics for the survivors. But the journey had just started. As (your name) travelled the infected city, he found more survivors and had to take them into custody to keep them safe. (Your name) finds the anti-biotics and runs back to the underground evacuation area. He gave the anti-biotics to the infected people and they soon cured. But the jouney was far from over. He soon found out his wife,whom he thought was dead, was hiding in the basement of a house in the middle of the city, where most of the zombies were lurking. Determined, he armed himself with armory and heads out to save his wife. He clears hordes of zombies and makes it to the house. As he opens the basement, he sees his wife sitting in there, in the dark, as he goes near her, she turns out to be a zombie, having no other choice, he shoots his wife in her head with a pistol. Feeling grief and sorrow, he determines to have a strong heart, and survuve the apocalypse.