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 his army. To rescue the hostages, the player must find along every stage the hostages, and take them to the exit of the building, avoiding the enemies. In each stage the player must rescue a different number of hostages. To do this our hero has a limited time and a unlimited ammo. There are a high-scores table for the best players.