The Bloog you see in the painting above is typical of its species. Bloogs are green, one-eyed, egg shaped, with bird like feet, fangs, and large purple tongues. They are minimally intelligent, and almost always hungry. In fact, such is their hunger, that they have kidnapped your baby sitter, in exchange for the knowledge of the location of the Stupendous Sandwich of Chungella IV, the largest sandwich in the galaxy, revealed to them by your arch-nemesis Mortimer McMire, who intends to blow up the universe.

So begins the sixth installment of the Commander Keen series: Aliens Ate My Babysitter. You star as eight-year old Billy Blaze, a child genius, who defends the galaxy from alien threats with his homemade Bacon-With-Bean Megarocket, ray-gun and pogo stick. In your quest to reach Molly, who is been held captive on the Bloog home planet of Fribbulus Xax, you journey through various outposts, factories, and installations, facing off against a variety of enemies: the one-legged Bobba’s, the many eyed Fleex, and the Orbatrix, a large flying eye.

A debut hit id Software – then known as Ideas from the Deep – the first trilogy of the Keen series, released as Invasion of the Vorticons in December 1990 had been colourful, and revolutionary shareware hit. Though platform games had been a fixture on PC computers for several years, Dangerous Dave by iD founder John Romero being one example, no title had been able to compete with the side scrolling platformers available on the Nintendo and Sega Master System. Simply put, PC graphics cards of the day were not powerful enough to redraw the entire screen fast enough as the character moved left to right.

Forced to innovate, John Carmack, the programming prodigy at id, had developed a method of tile refresh which pushed most the screen to one side so that only newly-visible portions of screen had to be redrawn. Proud of the innovation, the id team developed a demo of the first level Super Mario Bros. 3 and presented it to Nintendo, who rejected it because they wanted Mario to remain a Nintendo exclusive. Deciding to develop their own platform game, they borrowed computers from their employers SoftDisk, and programmed Commander Keen in their spare time.

Lead designer on the Keen project, Tom Hall incorporated many of his childhood memories into the production: it could be the eight-year-old Tom Hall standing on the surface of Xax in his red sneakers and Green Bay Packers football helmet. Keen was everything that Hall had wanted to be as a child. “Basically, Commander Keen is me” Hall said in a recent interview. “I didn’t have a 314 IQ, but I was in red sneakers and grew up in Wisconsin, and I wrote sci-fi stories as a kid…I went away and wrote in fifteen minutes wrote the paragraph you read in the first game, and read it to John Carmack in a Walter Winchell voice…we just rolled with it.”

The Vorticons Trilogy was an immediate hit, and successfully recreated the Nintendo feel. Its success convinced Romero, Carmack, and Hall that they could strike out on their own with their own company; starting with Keen Dreams, an engine experiment developed for Softdisk which introduced a more powerful graphical capability, specifically a tilted perspective, and cartoony art style. The plot: Keen is captured in his sleep by the Dream Machine, a device controlled by the evil potato King Boobus of the dream world Vegetable Kingdom. Keen must defeat Boobus whilst freeing other children who have been captured.

The Keen reached its zenith in the two-part Goodbye Galaxy series followed, with Aliens Ate My Baby Sitter sandwiched in-between. Holed up in wintery Madison Wisconsin, the games were developed in a matter of months; Hall, Carmack, and Romero working around the clock to create three full length titles full of attractive vistas, humorous cartoon enemies, and a tuneful soundtrack, which combined to provide perfect platforming fun. Goodbye Galaxy charts Keen’s efforts to thwart the efforts of the mysteries Shikadi, who are attempting to destroy the galaxy with a diabolical Armageddon Machine. The first episode Secret of the Oracle was issued as shareware, with the concluding Armageddon Machine released following the development of Aliens Ate My Baby Sitter, which was released commercially.

Though not as financially successful as the Vorticons Trilogy, the Goodbye Galaxy games and are fondly remembered by fans and Hall alike. “I think the overall art design was cooler, though I have a definite place in my hear for the original Keen development…the tilted perspective made things look really cool, but the levels took longer to make,” Hall recalled.

According to David Kushner’s id biography Masters of Doom, the team partially blamed the poor sales on what they felt was a poor box, designed by a company that designed packages for Lipton Tea. Drawn by Ken Rieger, who also designed the box art for id’s Wolfenstein 3D Apogee’s Blake Stone: Planet Strike, it imagines Aliens ate My Babysitter as a classic 1950s B-Movie, much in the way that Hall originally conceived Keen as a pulp sci-fi action story.

In the aftermath of producing the second Keen trilogy, id began developing Wolfenstein 3D, and never returned to Keen. The promised follow-up series, The Universe is Toast, was never produced, which is a shame if what Tom Hall has stated as his intentions for the game – a Super Mario 64 style experience that would have pre-dated that revolutionary title – had come to pass. A Gameboy Color revival in the early 2000s was a pale imitation of Keen’s former glories.

A quarter century on from its release, a generation of middle aged gamers are now just as nostalgic for their childhood days playing Commander Keen as Tom Hall was for his childhood in the 1970s. Keen was the Mario of the early 90s PC generation. With the nostalgia factor in modern gaming more potent than ever however, perhaps one day soon, Keen might pick up his football helmet and pogo stick, and save the universe once more. “I do miss the good ol’ days of Keen,” Hall has stated. “I love the universe and the gameplay, and I’d love to make another chapter in the saga. We will see how the future unfolds.”