Marine Wars consists of four scenes - a fight between battleships by day and by night and a battle between fighters and battleships by day and by nights.
At night you can not see the top row of enemy ships, but when a shell hits a ship and explodes the screen will light up for four seconds and the ships will appear. The enemy starts out with nine battleships and 30 fighter aircraft. You begin with three battleships.
The joystick is used to move your battleship to the left and right, and to fire shells at enemy ships and planes. If you fire a shell when you ship is moving, the shell will go in the opposite direction to where the ship is heading.
Points are awarded when you hit any battleship, an enemy fighter, an enemy torpedo, an enemy bomb and an enemy MTB.
Although this game is fairly simple, it does have some effective graphics and is also very colourful.