Quarantine Zombies is a tense first-person survival simulator in which the main objective is to hold the last line of defense in Chicago, ravaged by an epidemic. The protagonist controls the only remaining checkpoint in the northern part of the metropolis. Their daily routine boils down to thoroughly screening refugees attempting to leave the quarantine zone. Specialized equipment, including a body scanner, is used to identify those infected or smugglers. Each survivor faces a moral dilemma, as their fate depends on the soldier's decision. Some characters will try to influence the verdict through dialogue. The ultimate goal of the entire operation is to hold out for 30 days until army reinforcements arrive.