In game you play the role of Commander Keen: an eight year-old genius by the name of Billy Blaze, who builds an interstellar spaceship from his mom's vacuum cleaner. When Billy learns that the Earth is in danger, he dons his brother's football helmet to become Commander Keen -- Defender of the Earth!

his is the second game in the first trilogy of Commander Keen, called Commander Keen: Invasion of the Vorticons.

In this episode a Vorticon Mothership is poised above Earth, preparing to destroy every major city within their deadly Tantalus Ray!

Keen's mission is to sneak aboard the ship and stop these evil Vorticons from blowing up the Earth. In order to do this you need to find and destroy each X-14 Tantalus Ray, powered by cells from the big purple Space Amoeba. You need to find your way in the ship to each Tantaulus Control Room. You start in the ship's galley, and must find items to help you on your quest. You already have a Vorticion Hyper-Pistol, which has almost no ammunition at all and, of course, the trusty pogo stick from your Mars adventure.