In Invaders, you are the lone protector of your homeland against an alien fleet of alien invaders. Use the arrow keys to move your ship left and right on the game screen, and the space bar to shoot your weapons. The enemies will continue their advance unless you destroy all of them. As you destroy more of the enemy ships, they will descend more rapidly and be harder to destroy.

Another enemy ship will occasionally move across the top of the game screen to steal the last digit from your score. Destroy this ship before it has a chance to do that, or before it leaves the game screen to get your score back. Once this ship is destroyed, it will drop a package that will give you more advanced weaponry if you pick it up. You have three chances to destroy the enemy fleet. Keep firing and collect the highest score you can to win!