Nuclear war, zombie outbreaks, meteor strikes, economic collapse, alien invasion, no matter how it happens an apocalypse makes for a unique and engaging setting to run a campaign in, even for a jaded GM.
Here’s a few quick tips that can make a good zombie or other post apocalypse game a great one, and keep the group coming back (from the dead?) for more.
Termites, in certain places, make homes that can be eight meters high and only a half meter wide. They are built facing North to South to take advantages of the suns travel, maximum heat in the morning and evening and little in the afternoon. Imagine grassy plains with vertical structions facing a certain direction all over the place. Ambush? Maze? New creature? Larger structures?