Commander Keen is a series of video games developed by id Software in the early 1990s. The series focuses on the adventures of Billy Blaze, an 8-year old boy who travels through space and assumes the identity "Commander Keen". The series was successful at replicating the side-scrolling action of the Nintendo Entertainment System Super Mario Bros. games in DOS. The cartoon-style platform games are notable for their pioneering use of EGA graphics and shareware distribution, and because they were some of the first games by id Software (which went on to develop blockbusters like Doom and Quake). The games were also exciting to the PC gaming community of the time because of John D. Carmack's smooth-scrolling graphics engine. Although developed by id, most of the Commander Keen games were published by Apogee Software, an already established DOS shareware game publisher. Tom Hall is Commander Keen's designer and the creator of its universe. The games were made available on Steam on August 3, 2007.
Seven official Commander Keen games were released for the PC under MS-DOS. They are divided in mini-series, and are considered "episodes" of the full series. Under the Apogee version of the shareware model (the "Apogee Model"), the first episode of a series was usually available as shareware. The eighth game in the series is available exclusively for the Game Boy Color.
Commander Keen in Invasion of the Vorticons
- 1. "Marooned on Mars" (first released as shareware on December 14, 1990)
- 2. "The Earth Explodes"
- Keen returns to Earth only to find the Vorticon mothership hovering above with its deadly X-14 Tantalus Ray cannons locked on to eight of Earth's greatest landmarks: the Big Ben (London), the Sphinx (Cairo), the Sydney Opera House (Sydney), the Statue of Liberty (New York), the Eiffel Tower (Paris), the Colosseum (Rome), St Basil's Cathedral (Moscow), and the White House (Washington D.C.). Keen has to find and deactivate each of the cannons to save Earth. Unlike the first game which had a happy and friendly atmosphere, almost everything in this game is hostile towards Keen, from the floating machine gun robots to the electrified floors. The engine has more features than the first episode, such as light switches and moving platforms.
- 3. "Keen Must Die!"
- Keen travels to the Vorticon homeworld in search of the mysterious Grand Intellect that has directed the Vorticons toward Earth. The game features the cities, parks, and suburbs of the Vorticons, and their women, children, pets, and mechanical toys make up the enemies. The Vorticon alphabet is also decoded in a school house, allowing for the player to travel to the other in-game locations and read the Vorticon signs.
- 3.5. "Keen Dreams" aka "The Lost Episode" (published as shareware by Softdisk)
- After refusing to eat his vegetables, Billy is sent to bed by his parents. He falls asleep, only to awaken in a strange vegetable kingdom led by the evil potato king Boobus Tuber, who has imprisoned other sleeping children there. In the dream world, Keen does not have his trademark raygun and pogo stick, but has to defend himself with "Flower Power" seeds that temporarily turn enemies into flowers.
Commander Keen in Goodbye, Galaxy!
- 4. "Secret of the Oracle" (first released as shareware on December 15, 1991)
- Keen's newly finished homemade faster-than-light radio picks up a plot by the Shikadi to destroy the galaxy. He rushes to the planet Gnosticus IV to consult the Keepers of the Oracle, but discovers that they have been taken captive. Thus, the gameplay centers on Keen finding and rescuing the eight elders. This episode features huge levels and a wide variety of enemies, such as rocks that only move when Keen's back is turned, and modified game mechanics. The game also features a mini-game called "Paddle War", a remake of the video game Pong, though this version is vertical instead of horizontal.
- 5. "The Armageddon Machine"
- After getting information from the Oracle, Keen lands on a massive Shikadi space station, the Omegamatic, nicknamed the Armageddon Machine, and seeks out the mysterious Gannalech. The gameplay centers on Keen advancing through the Omegamatic to deactivate it.
Commander Keen in Aliens Ate My Babysitter!
- 6. "Aliens Ate My Babysitter!" (published commercially only by FormGen, Apogee resold it as a retailer; now discontinued)
- When Keen's babysitter Molly is abducted by the Bloogs, Keen must come to her rescue by fighting his way through the inhabitants of the planet Fribbulus Xax. This is the last episode of the original Keen series.
Commander Keen (GBC)
- In 2001, Activision published a Commander Keen game for the Game Boy Color, titled Commander Keen. The game, although developed with id's permission, did not involve any of the original Commander Keen developers, but was instead a David A. Palmer Productions game. Tom Hall, creative director and designer of the original Commander Keen series, has stated that he does not consider the GBC game "canon by any means".
Other releases and cancelled games
- On August 3, 2007, episodes 1-5 were rereleased on Steam as part of the id Software game addition to Steam. The package was priced at USD$4.95 on release. In this release, the DOSBox emulator is used to run the games on Microsoft Windows.
- A Commander Keen game for the Nintendo Entertainment System was planned. It was supposed to be released by a major American Nintendo publishing company.
- An additional trilogy, tentatively titled The Universe is Toast!, was planned for Christmas 1992, but it was never produced, as id moved on to Wolfenstein 3D and then Doom. Tom Hall claims that he intends to make a new game if he ever reclaims the intellectual property rights to Commander Keen.
- Monkeystone Games planned to release Keen Chronicles through a Softek International April 2002. It would have consisted of all Keen games packaged together for Microsoft Windows and Pocket PC, but it never got out of the planning stages, and was never even officially announced. Fan website Keen.Retodon8.net features the logo that would have been used.
Billy Blaze is an eight-year-old boy genius who has constructed a spaceship in his backyard from old soup cans and other household objects, called The Bean-with-Bacon Megarocket. When his parents are out and the babysitter falls asleep, he dons his brother's Packers helmet and becomes Commander Keen, Defender of Earth.
In the first game, Keen is exploring on Mars when aliens steal four spaceship components that he must get back. The aliens are the Vorticons, a fierce dog-humanoid race that had an outpost on Mars. Keen travels through different Martian cities, and eventually recovers all the missing parts. However, when Keen gets back to Earth, he finds the Vorticon mothership looming over the planet, with its cannons ready to attack. In the second game, Keen infiltrates the mothership and has to disable each of the Tantalus Rays targeting different Earth cities. During this adventure, Keen learns that the Vorticons used to be a peaceful race, but were enslaved by the mysterious Grand Intellect.
After disabling the cannons, Keen travels to the Vorticon homeplanet, Vorticon VI. In the third game, Keen has to face the Vorticon masses in their cities, all ready to kill Keen. After fighting through many levels of Vorticon-infested cities and military installations, Keen arrives at the lair of the Grand Intellect. There he discovers that the leader of the Vorticons is actually his school rival Mortimer McMire (whose IQ is a single point higher than Keen's). In the final level, Keen has to disable the "Mangling Machine", a large apparatus with many crushing parts controlled by Mortimer. Keen eventually defeats Mortimer and frees the Vorticons.
Unbeknownst to Keen, the Mortimer he had defeated was only an android duplicate. The real Mortimer goes on to lead the Shikadi, a race of energy beings who name him the Gannalech. In episodes 4 and 5, he attempts to destroy the galaxy with the Shikadi Omegamatic, but Keen stumbles on a radio message mentioning the Shikadi plans. In the fourth game, he travels to Gnosticus IV, to learn more about the Shikadi from the Oracle. However, when he gets there he discovers that the guardians of the Oracle have been captured by the Shikadi, and are imprisoned in the Shadowlands of the planet. Keen travels through dangerous forests, caves, and islands, and is finally able to rescue all of them. The guardians activate the Oracle, which tells Keen about the Omegamatic being near completion, and reveals the location of the station, in the Korath system.
In the fifth episode, Keen travels to Korath III and enters the Omegamatic to destroy its core, the Quantum Explosion Dynamo, and stop the destruction of the galaxy. After avoiding several defense systems, Keen is able to reach and destroy the device. There he learns that Mortimer was the Gannalech, and his intention to destroy the universe is revealed. In the sixth and final episode, Mortimer has Keen's babysitter kidnapped by the Bloogs to distract him. After travelling to Fribbulus Xax, Keen explores the alien planet and saves Molly from being eaten.
William Joseph "Billy Blaze" Blazkowicz II, a.k.a. "Commander Keen" or "Keen", is the main character of the games, and the player's alter ego. Keen is an eight-year-old boy genius purported to have an IQ of 314 (a reference to π). Keen is the grandson of William Joseph "B.J." Blazkowicz (the Allied war hero of Wolfenstein 3D). Keen's parents are Arthur Kenneth Blazkowicz, a television talk show personality in Milwaukee, and Susan Elizabeth McMichaels. Keen's father changed his last name to Blaze for show biz. Keen has one older brother and one possibly younger sister, names unknown. During Keen's first adventure in Mars, one of the friendlier martian aliens, a green critter with an eye on a stalk (called a Yorp) sneaked into his spaceship and came along home. Keen adopted him and named him Spot.
The main antagonist of the series is Mortimer McMire, Keen's arch-rival at school. Mortimer is an evil eight-year-old genius, and has an IQ of 315, as opposed to Keen's 314. In episode 3, it is revealed that McMire was somewhat of a bully towards Keen, beating him up and giving him swirlies because of the latter's lower IQ. McMire wears a black football helmet. Mortimer's older sister, Molly, is Keen's babysitter.
Mortimer's main goal is to destroy all beings of lesser intelligence (i.e. the entire galaxy). In the first game series, Mortimer enslaves the Vorticons, a once peaceful alien race, and attempts to use them to destroy Earth. In the second game series, Mortimer convinced the Shikadi, a race of energy beings, to destroy the galaxy. Mortimer's next plan was to destroy the entire universe, but as the trilogy called The Universe is Toast was never created, his plans were left on indefinite hiatus. However, Mortimer had another couple of appearances: he is responsible for Keen's babysitter's abduction in episode 6 of the series, and in the Game Boy Color release of Commander Keen, Mortimer is responsible for another alien race attempting to rule the galaxy.
Creation and development
John D. Carmack, a game programmer at Softdisk, discovered a trick that would allow smooth-scrolling graphics in PC games, but only with the 16-color EGA graphics card. Carmack and his Softdisk colleague Tom Hall kept the technology from Softdisk and used their own time to put together a clone of the first level of Super Mario Bros. 3, except for the hero, which they replaced with Dangerous Dave, a character from John Romero's games for Softdisk. They called their creation Dangerous Dave in Copyright Infringement. After Romero saw their demo in action, he and Jay Wilbur, project chief at Softdisk, suggested that they finish the Mario clone. The team then created a perfect PC port of Super Mario Bros. 3 in a week and approached Nintendo with their creation, who declined to enter the PC market at that time, but did congratulate the team for their efforts.
John Romero was later contacted by Scott Miller of Apogee, who, after seeing some of id's work, advanced the team $2,000 for the development of Commander Keen, starting a profitable business relationship that would last until id Software self-published Doom.
The first trilogy, Invasion of the Vorticons, was completed in three months. After developing it the team left Softdisk to form id Software. However, the developers of id had a contract with Softdisk requiring them to write several more games, one of which became Keen Dreams. Keen Dreams is sometimes referred to as "Keen 3.5", "Keen 7", or the "Lost Episode", as it was never distributed by Apogee.
The sequel to Invasion of the Vorticons was supposed to be another trilogy. Episode 6 (Aliens Ate my Babysitter!) was originally planned to be part of it, along with episodes 4 and 5 (which ended up together as Goodbye Galaxy!), but was later changed into a stand-alone commercial episode. Episode 6 was actually developed before episode 5.
Invasion of the Vorticons
In Invasion of the Vorticons, the player can walk left and right on the screen, and jump to get on higher platforms. Some of these are semi-solid and can be jumped through from below. In the first game the player finds a pogo stick, which he can use for a continuous jump. This makes Keen harder to control, but allows the player to jump twice as high if he presses the jump button at the right moment. Keen keeps the pogo stick for the rest of the series.
The player will find an alien ray gun, which he can use to fire slow moving projectiles straight left or right to kill enemies. Some enemies die after one shot, some after more, and others are impervious to the ray gun. Unlike similar platform games like Bio Menace, the hero does not have a health bar. If Keen touches an enemy, he immediately loses a life. Enemies include Martians (in episode 1), and Vorticon or Vorticon-related creatures (in all three episodes). See Vorticon for details on most of the enemies. There are also several hazards in the games that will kill the player when touched, such as fire and acid.
Items found in the levels include:
- Rayguns and Charges: Provide additional shots.
- Score Items: Usually in the form of sugary foods and beverages, these items give Keen varying amounts of points (from 100 to 5000 points). The items worth the most points are generally difficult to access. Collecting enough (20000 points) will get the player another life.
- Colored Keycards: Red, yellow, green, and blue cards open doors with corresponding colors, and are usually necessary to collect to complete a level.
The second episode introduces moving platforms which can transport Keen, and switches which usually extend bridges over gaps in the floor. Some switches are light switches which can be used to turn off the light, making some enemies afraid to jump. The third game includes a power-up in the form of an ankh which acts as a temporary god mode.
While travelling between levels, Keen is viewed from above on a map; this is the only place where the player can save the game. Some of the levels are optional and can be skipped. Episodes 1 and 3 contain a secret level which is not easily accessible.
In this game Keen does not have his pogo stick, so he cannot jump as high anymore. However, he can duck, and drop down from the semi-solid platforms if the player presses the jump key while ducking. An addition to the platforms are firemen's poles, which the player can use to climb to higher platforms, and even jump up on them if he times the jumps right. This and further episodes use a slanted 3D look for the levels.
Instead of the ray gun, Keen is armed with "Flower Power", small pellets he can collect and throw left, right, straight up, or, when falling, straight down. The pellets are used up if they hit an enemy, but if Keen does not hit anything, he can retrieve and re-use the pellet if he is quick enough. Enemies that are hit are not killed, but turned into a big, stunned flower for several seconds, the actual time varying with the difficultly level. All enemies are based on fruit or vegetables, such as: Tomatooth, Broccolash, and Frenchy; whereas the collectible score items are sweets.
Keen Dreams introduces three difficulty levels. Another improvement is that the player can now save anywhere and at any time.
Goodbye Galaxy! and Aliens Ate My Babysitter!
In Goodbye Galaxy! and Aliens Ate My Babysitter!, all the improvements from Keen Dreams are kept, except for the "Flower Power". In these episodes the player can look up and down by pressing the corresponding movement keys for a short while. This effectively scrolls the screen up or down. Keen also has his pogo stick again. If Keen narrowly misses a jump, he can grab onto the edges of most platforms, and climb up. The slanted 3D look of the levels is used to add hidden passages in the ceiling and right-side walls. Keen can also enter doorways leading to other zones, if the player stands in front of the doorway and presses the up key.
Keen uses a Neural Stunner as a weapon, which he can fire in 4 directions, and has a faster rate of fire. It renders enemies unconscious instead of killing them. This stun does not wear off for most enemies, yet some enemies are only momentarily paralyzed by it, and it does not work on a few enemies. In episode 4, the enemies are mostly based on animals or nature; in episode 5, they are mostly robots and electrical creatures. In episode 6, the enemies are invented and alien-like.
The levels are filled with many types of items:
- Neural Stunner: Replaces the raygun.
- Score Items: The same kind as those in Invasion of the Vorticons; the ones worth more are now also hidden in walls. In addition, there are items that give 2000 points.
- Key Gems: Replacing the colored keycards from Invasion of the Vorticons.
- Raindrops/Vitalin/Vivas (depending on the episode): Every 100 collected grant Keen an extra life.
- Life Water Flask/Keg o' Vitalin/Queen Viva (depending on the episode): Rare and generally difficult to obtain items that grant Keen an extra life.
Episode 5 has keycards that are needed to open the final doors in some levels. Episode 6 features very large switches Keen needs to either jump on, or headbutt to use.
The level maps feature obstacles which can be overcome with items retrieved, or actions performed, in the regular levels. Episodes 4 through 6 contain a secret level, and in order to find it the player has to thoroughly explore optional parts of the game world.
The games also include a minigame called Paddle War, a clone of Pong, programmed into Keen's Wrist Computer, which functions as the main menu. (The minigame, although titled differently, can be found in Catacomb 3D as well.)
An important part of Keen games is their humor and cartoon-like atmosphere. Humorous references can be found in the characters, enemies, items, back story, locations, levels, signs, and animations. Tom Hall has stated that many elements of the games were inspired by Chuck Jones's Duck Dodgers in the 24½th Century. This can be seen directly at least in two references to the Acme Corporation from Looney Tunes: in the world-map for episode two, which is the blueprints of the Vorticon Mothership, there is a small sign in the Standard Galactic Alphabet (see section below) that says "Blueprint — Acme". Also, at the end of episode four, the Oracle has the sign "Acme Oracle" written on it in the same alphabet.
Some other humorous references include the following:
- In episode 3 of "Invasion of the Vorticons", Foobs are creatures who are afraid of everything, and run away from Keen. If Keen touches them, they die, in contrast with Keen dying when he touches an enemy.
- In the "Pyramid of the Moons" level of Secret of the Oracle, if Keen stands on top of one of the crescent moon symbols on the floor, after a short while he will moon the player.
- In the "Pyramid of the Moons" level, Keen can gain access to a secret level by gathering inchworms under him at a certain point. He must gather 12, and then a giant foot appears (since 12 inch (worms) = one foot).
- At the end of the secret level of Secret of the Oracle, which is very difficult to complete, what appears to be one of the guardians of the oracle is actually their janitor, kidnapped by mistake.
- In "Secret of the Oracle", the Dopefish is mentioned to be the 'second dumbest' creature in the whole universe, referring to the Ravenous Bugblatter Beast of Traal from The Hitchhiker's Guide to the Galaxy. Similarly, after getting the sandwich in the "Bloogfoods Inc." level of "Aliens Ate My Babysitter" Keen says "This is the second biggest sandwich I ever saw!"
- In episodes 4, 5, and 6, if Keen is left idle for several seconds, he will look directly towards the screen with his hands on his waist, looking impatient, then shrug his shoulders. After a few more seconds he will grab a big red book out of his pocket, sit down, and start reading, flipping pages occasionally. He will continue to do this until an action key is pressed. In "Keen Dreams", Keen will fall asleep instead of reading a book.
Standard Galactic Alphabet
The Standard Galactic Alphabet, also known as SGA, is the writing system used to depict Omnispeak, the alien language of choice in the galaxy in the Commander Keen fictional universe. The player usually first discovers the alphabet in the first Commander Keen game, Marooned on Mars, where Keen telepathically hears an alien inside a shrine say: "It is too bad you cannot understand the Standard Galactic Alphabet, human".
In reality, it is a simple substitution cipher created by Tom Hall for the Commander Keen series. Originally for Keen 1 he drew some graphics for Exit signs which he made look a bit more alien by changing the ordinary Latin letters a bit. After that he added other signs saying "hi" and "this is neat" (near rayguns), and he ended up creating conversions for the other letters of the Latin alphabet for the signs to resemble writings in an alien language. Because the texts are still in English, however, it is not an artificial script.
Besides the 26 letters, SGA uses spaces for its interword separation, and in some instances uses a ·—· symbol as a full stop. In the Keen 1 level in which most players obtain the pogo stick, a short horizontal dash above a long one appears on either side of the word "POGO", perhaps as quotation marks. No other known punctuation exists. There is also no capitalization, and numbers are absent.
Players of the Keen series that spent the necessary time could figure out SGA by looking at the many signs throughout the games. While the original Keen only has fifteen letters displayed anywhere (A, B, C, D, E, H, I, K, L, N, O, S, T, X and Y), later games have more. Keen 3 is particularly helpful, since it has a relatively large number of signs with both SGA and Roman letters.
Also in Keen 3 a sign with the complete SGA can be found in the secret level, similar to the Rosetta Stone. Another alphabet sign can be found in Keen 6 in the Blooglab Space Station level. Knowing the complete alphabet is necessary for the player to decipher a letter which explains part of the storyline at the end of Keen 5.
In addition to printed signs within levels, the SGA was found in level design features. There is a curse word hidden at the beginning of Keen 2's "Paris" level, spelled in SGA. The misspelled word "FUCL" is made of yellow platforms inside a field of red platforms.
Joe Siegler later wrote a secret message that said "Dopefish lives" in the walls of a Rise of the Triad level. The story goes that during Rise of the Triad development, one of Tom Hall's instructions to the level editors was not to "write words in the levels with the walls". Joe asked about SGA, and that idea was approved, hence the "Dopefish Lives" message in SGA in one of his Rise of the Triad levels.
SGA has not had much other official use after that, but Tom Hall invented a syllabary to create a more complex "alien" language used in Ion Storm's Anachronox. After that, id Software created a simple substitution cipher very similar to SGA for the Strogg race in Quake 4.
Invasion of the Vorticons, Goodbye, Galaxy!, and Aliens Ate My Babysitter! were reviewed in 1993 in Dragon #197 by Sandy Petersen in the first "Eye of the Monitor" column. Petersen gave the Commander Keen series 4 out of 5 stars.
A number of fan-made Commander Keen games have been created, mostly using Klik & Play, Click & Create, Game Maker and similar game construction software. The Public Commander Keen Forum has a forum devoted to the announcement and discussion of these unofficial Keen games.
CloneKeen is a game engine recreation that requires the original datafiles, and supports episodes 1 through 3. It was programmed on and off by Caitlin Shaw since 2003, and finally released on October 18, 2005. It is available for GP2X, Linux, Windows and Dreamcast. It was also ported to the PlayStation Portable in February 2006, the Nintendo DS in October 2008 and the Wii in November 2008.
In the years since the release in early 2002 of utilities to modify the levels and graphics in the original Keen series, more than fifty mods have been made. Most of these have Commander Keen as the protagonist, but some use the Commander Keen engine to develop an entirely new game. Probably the most thorough of these efforts is Commander Keen 7: The Keys of Krodacia by Ceilick, a mod of episode 4 of the series, and Commander Keen 8: Dead in the Desert by Ceilick, a mod of episode 6 of the series. The tools and utilities used to modify the games, as well as a body of accumulated knowledge of the Keen code, are still being updated and improved. A third episode Commander Keen 9: Battle of the Brains by Ceilick, a mod of episode 5 of the series, is now in production.
Keen in other games
- The Dopefish, an enemy character from Secret of the Oracle, has become one of the biggest video game in-jokes and appeared in many games over the years (such as in all Quake games except Quake 4) and continues to make hidden appearances in modern titles.
- Keen appears as a hostage in Apogee's Bio Menace episode 2, level 6. In the same episode in level 10, a yorp is seen in one of the incubators. Also in the same level there is a room filled with items from Bio Menace, Commander Keen and Duke Nukem.
- Commander Keen makes a cameo appearance in level 32 'Grosse' (a secret level) of Doom II (not in German releases). He is displayed as hanged with a noose and the player can shoot him, making him explode in blood and authentic PC speaker sound effects. At least two Commander Keen skins have been created for the Doom source port Doom Legacy, cementing Keen's connections with Doom in a more positive light.
- In Apogee's Duke Nukem episode 1 level 7, Dr. Proton briefly mentions Commander Keen while threatening Duke.
- In Apogee's Crystal Caves Keen's helmet appears in levels 8 and 10 of episode 2, and in episode 3 level 2. Yorp herding is mentioned in the story.
- Commander Keen's Teddy Bear from episode 1 is in Apogee's Secret Agent as a bonus item. Commander Keen himself is mentioned in the instructions that describe the Teddy Bear.
- The Gargs from Episode 1 closely resemble enemies in Monuments of Mars.
- In Apogee's Paganitzu episode 2 level 15 there is a yorp.
- Keen is mentioned if the code "BAT" is entered in Wolfenstein 3D and Spear of Destiny.
- Keen is on the default high score list of Apogee's Monuments of Mars, Crystal Caves, Paganitzu, Realms of Chaos and Stargunner.
- Redwood Games' Pickle Wars mentions Commander Keen in Episode 1 Level 10.
- In Apogee's arch-rival, Epic MegaGames' Jill of the Jungle, episode 1 includes a news bulletin taking a swipe at Keen, who it claims has been forced into retirement by "those cool Epic heroes".
- In the computer game Guild Wars, the fourth rank of the commander title track is "Keen Commander".
- In Epic MegaGames' Jazz Jackrabbit 2, a signpost in one stage proclaims that Jazz's brother, Spaz Jackrabbit, ate the Dopefish.
- In Wolfenstein RPG, a character named Commander Keen aids B.J. Blackowitz in his journey.
- In Anachronox, apartment C3 of the Tenements belongs to a 'B. Blaze.'
- ↑ http://store.steampowered.com/news/?appids=9010
- ↑ "The Apogee Legacy #4 - Tom Hall", 3D Realms Website, January 30, 2006. Retrieved on October 15, 2006.
- ↑ ROME.RO Mega Photo Gallerytron- powered by SmugMug
- ↑ 4.0 4.1 4.2 4.3 4.4 "A Look Back at Commander Keen", 3D Realms Website, December 14, 2000. Retrieved on October 15, 2006.
- ↑ id Software. The Official Hint Manual for Wolfenstein 3D. Apogee Software
- ↑ Kushner, D. (2003). Masters of Doom: How Two Guys Created an Empire and Transformed Pop Culture. Random House. ISBN 0-37-550524-5
- ↑ "There is actually a filthy word somewhere in Keen 1-3, spelled in the Standard Galactic Alphabet, made of yellow platforms inside a field of red platforms." http://www.3drealms.com/keenhistory/keenhistory3.html
- ↑ 20 Questions For Joe Seigler
- ↑ Petersen, Sandy (September 1993). "Eye of the Monitor". Dragon (197): 57–62.
- ↑ "Voici la première version de mon adaptation de CloneKeen sur DS." In English, "Here is the first version of my port of CloneKeen to DS." CommanDSKeen V1.0 disponible, Portabledev (French), October 19, 2008. Retrieved on October 20, 2008.
- ↑ http://gbatemp.net/index.php?showtopic=115515
- Official Apogee Pages
- Commander Keen: Invasion of the Vorticons Official Apogee page
- Commander Keen: Goodbye Galaxy! Official Apogee page
- Commander Keen history Official Apogee page
- By the Keen Community
- Beyond the Pogo – Site containing content created by the Keen community; also hosts the Keencyclopedia
- CloneKeenPlus – Interpreter for Commander Keen 1-3
- KeenWiki - Commander Keen dedicated Wiki
- 'Commander Keen series at MobyGames
- Commander Keen Fans – Site dedicated to creating and hosting fan works of Commander Keen
- The shareware games can be downloaded from the Apogee pages above or the following sites
- DOSome Games: Commander Keen Windows install