Zylogon is an isometric shooter where the screen constantly scrolls as you break down the defences of a fortress belonging to the Zylogon. They are a race of androids who threaten our existence so you must fly your ship down a corridor avoiding or bombing alien crafts as well as avoiding walls. If you are hit by a ship or collide with a wall then you lose one of three lives. You also have a fuel gauge to look out for and this slowly decreases the further into the game you get but there are fuel dumps scattered around which need bombing to increase your fuel. Once a timer gauge empties then you move onto the next level which sees you able to shoot ships moving towards you on a black background. When a timer gauge again runs out then you fly back down the corridor with just your bombs again.