It takes place aboard a spaceship. The story takes place after all the official Keen games, and is an interpretation of a possible storyline for Commander Keen: The Universe is Toast.
In this episode, having stopped the Shikadi Armageddon Machine and saved his babysitter Molly from being devoured by the Bloogs of Fribbulus Xax, Commander Keen finally sits down to decypher the mysterious message he found in the command room of the Q.E.D.
Upon translating, Keen was shocked to discover that Mortimer's plans extended far beyond the destruction of Earth--or even the Galaxy! No, Mortimer's plan is to destroy the Universe!
Checking in on his still-groggy parents, (whom he had recently nursed back to conciousness via ice cream,) young Billy once again donned his brother's football helmet and blasted off into space, destination: McMire's ship.
After a considerable trip, Keen's ship slowed out of hyperspace and crept up to the underside of Mortimer's stealthy mothership. A simple frequency scan granted him access through some bay doors, and without a second's hesitation, Keen set out to dismantle key structures in this Universe-threatening ship!
Tank BotTank Robot replacement.
Little Candies100 points.
Yummy Cookie200 points.
Juicy Hot Dog500 points.
Fruit Snacks1,000 points.
Bowl of Nachos5,000 points.
Hyprician LinkPart required to finish the game.
Keygems used to open doors.
Kirimpul PistonPart required to finish the game.
Neuclidium CorePart required to finish the game.
Five extra shots.
Pogoing allows reaching otherwise inaccessible places (obtained upon entering the first level).
Ponart SensoscopePart required to finish the game.
- 81: EndingRequired?NoPoints0Ammo0
- 90: Title screenRequired?NoPoints0Ammo0
There are three levelpacks made for this mod.
- KeenRush has made a levelpack called xky1tuned. The 16 new levels of the level pack are considerably more difficult than the original levels of the mod.
- A Keen Community Levelpack for Keen X has been started by Fleexy. Release 2 of 2010-03-14 features 10 levels.
- Years later after his first one, KeenRush released another levelpack called xky1rooms. It's a remake of 14 of the levels from the original mod as one-room levels.