You must protect the last outpost of the free. If you destroy it, the free world is doomed.
In the tanks, but no tanks, you are a lone tank to defend your outpost against waves of phantom tanks. These tanks appear and disappear on the screen. There are a total of twenty Phantom tanks on the level, but not all on the screen at one time. After twenty phantom tanks are destroyed, you move to the next level. In one level, you have the walls of a maze to slow down the enemy. The two levels, you have just a small island as a shield. The three levels, it's you and the enemy, and nothing else. You have five tanks on the level. If all of your tanks and your bases are destroyed, the game is over.