The first game in the series portrays the story of a lone survivor named Jack, attempting to hold out against an unrelenting zombie horde from the safety of his fortified barricade. The game is a multi-level base defense game broken up by rest periods where the player must search for weapons and other survivors, as well as repairing the barricade in preparation for the next wave of enemies. After holding out for 20 days, Jack and his group are rescued by a passing military helicopter.

The player steps into the shoes of a survivor named Jack, who finds himself in the midst of a massive zombie outbreak. Fortunately, he has just completed the construction of a sturdy barricade, in addition to having stockpiled a large amount of supplies before the outbreak began. Now, he must search for weapons and survivors and repair the barricade during the day, while fending off the encroaching zombie hordes during the night.