Cannon Fighter

Early MSX 1 game where you control a little man with a cannon tasked of defending a military base in the desert. You have to calculate your shots to destroy the tanks before they arrive at each of the base walls. Once they do, you lose that position to the enemy army and have to retreat to another position. After the 3rd retreat the base is shown and if you lose this time, the base is conquered by the enemy. Simple but effective little game.