From the webpage:
Zpocalypse is a survival board game set in a post-apocalyptic wasteland. Two to four players start in a basement/fallout shelter which can lead out to several base locations or even through the tunnels to sewer grates throughout the transformable board. Their survivors are trying to make it day to day in a world torn apart from the walking dead.
As in any survival game one needs food, guns, ammo, and more. Players go out into the wasteland and scavenge for supplies, or perhaps to find a new gun or melee weapon to fend off the next zombie attack.