You control the only disintegrator cannon with which you must protect the prison from the relentless onslaught of the Argons as they strive to liberate their Kings whom you have imprisoned for their crimes against the Empire. The Argons will dismantle the jail brick by brick until they have freed their nine Rulers. For each wave of Argons you destroy, another more determined one will take their place. Extra points are scored for shooting Argons holding bricks or Kings.