The game begins in the Supply Depot. You have a Standard Gun, 50 rounds of standard Shell ammunition, your trusty Mark 1, Mod 0 eyeball to aim with, and 10 supplies in reserve. If you like, you can spend the 10 supplies you have left to buy 10 additional rounds for your gun or save them for later. When you are ready to begin play, press the 'Man Defenses' button.
During a raid, enemy paratroopers will appear at the top of the screen, open their 'chutes, and begin descending toward your gun. It's up to you to stop them. The first few raids will give you an opportunity to get used to the Standard Gun and to the behavior of the different types of enemy troopers you face. After each raid is completed, a summary will appear, detailing your accomplishments during the raid and reporting on your supply state. Then, you will be returned to the Supply Depot to re-arm and re-supply in anticipation of the enemy's next attack.
