After centuries of human oppression the chickens have had enough. With the aid of kin from another galaxy, they have begun attacking Earth's defenses with millions of dropped eggs and asteroids. You, as the pilot who just wants to get a hamburger, are Earth's final hope for survival.

Chicken Invaders is the first part of a series of Space Invaders parodies where you control a space-ship while facing waves of asteroids and space chickens. Your movements are limited to a horizontal plane but are armed with a blaster which you can use to shoot the enemies. You can upgrade your weapons to spread or to missiles by simply getting enough points or by collecting the gift boxes the occasional chicken will drop.

Your enemies are the waves of chickens who move in patterns down the screen and shoot eggs at you. Coming into contact with them will also be detrimental to your survival. Accompanying the chickens are asteroids which in one wave go slowly diagonally across the screen and asteroids which plummet quickly down. All can be blasted given that they're shot enough.

After every nine waves of chickens you will face off against a boss chicken which is larger and more dangerous. This chicken will require a multitude of landed blasts to defeat. Of course you don't have to be the last pilot facing off against these invaders as the game allows for two people to play off the same keyboard. Whoever gets the higher score can afterwards post their score online.