In Piso Zero, the player takes the role of Mac, a hero that must rescue the people of 15 buildings that are now under the control of the evil Calawarr brothers and their army. To rescue the hostages, the player must find along every stage the hostages and take them to the exit of the building, while avoiding the enemies. In each stage, the player must rescue a different number of hostages. The hero has limited time and unlimited ammo. There is a high-scores table to keep track of the highest scoring players.