Urban Nightmare : Megagame of Chaos
The zombie apocalypse trope is well established in literature, movies, computer and board games. And in megagames too, with the first series of Urban Nightmare megagames played in 2012.
As a megagame, the Urban Nightmare games explore the higher level decision making during a major, potentially existential, crisis. In the movies and other games the zombie trope generally focusses on the individual or on small groups of survivors, but rarely explores how the world gets to that state. It all just happened and got out of control.