Red Alert Zombie Apocalypse

It happened very quickly. Yesterday everything was fine, but the night before the world turned into a huge meat grinder, where zombies prey on people. Your life is now divided into before and after the so-called events. You spent the night in hospital as a strong blow your head and can not remember anything. You woke up in the hospital is already empty, and when you are out on the street, it is very frightened. You need to escape from the city.