Editing Commander Keen (section)

==Titles==
===Games===
* '''''[[Commander Keen in Invasion of the Vorticons]]''''' is the first game in the series, released on December 14, 1990, for [[MS-DOS]]. It is divided into three episodes: "Marooned on Mars", "The Earth Explodes", and "Keen Must Die!", and the game was published through a [[shareware]] model whereby "Marooned on Mars" was released for free, and the other two episodes were available for purchase. It was developed by a team calling themselves Ideas from the Deep (or sometimes IFD Software),<ref name="ifdname"/> consisting of programmers [[John Carmack]] and [[John Romero]], designer [[Tom Hall]], artist [[Adrian Carmack]], and manager Jay Wilbur, and published by [[3D Realms|Apogee Software]]. The game, like the rest of the series, is a [[side-scrolling video game|side-scrolling]] [[platform game|platform video game]].<ref name="MOD6366"/>
* '''''[[Commander Keen in Keen Dreams]]''''' is the second game of the series, released in 1991 as a single episode; it is sometimes referred to as episode 3.5 of the series. It was developed for MS-DOS by [[id Software]], which had been founded by the Ideas from the Deep team after the success of the first game, and published through [[Softdisk]] as part of an agreement between the companies as the founders of id had been employees of Softdisk when they developed ''Vorticons''.<ref name="MOD6676"/> Id used the game, which stands outside of the general continuity of the series as a "dream" episode, as a prototype to test ideas they wanted to use in future games, such as a more advanced art style, [[parallax scrolling]], and gameplay changes.<ref name="MOD6676"/><ref name="IGNid"/> In 2013 a port was developed by [[Super Fighter Team]] for [[Android (operating system)|Android]] devices,<ref name="Android"/> and a 2014 [[Indiegogo]] [[crowdfunding]] campaign led to the original source code being released under [[GNU General Public License|GNU GPL-2.0-or-later]] and a release by Hard Disk Publishing through [[Steam (service)|Steam]] for [[Microsoft Windows]] and [[Linux]] in 2015, and [[OS X]] in 2016.<ref name="Indiegogo"/><ref name="SteamDreams"/> A [[Nintendo Switch]] version was released by Lone Wolf Technology in 2019.<ref name="Switch"/>
* '''''[[Commander Keen in Goodbye, Galaxy]]''''' was released for MS-DOS on December 15, 1991, as the second main game in the series. Consisting of episodes four and five of the series, "Secret of the Oracle" and "The Armageddon Machine", and stylized as ''Commander Keen in Goodbye, Galaxy!'', it was developed by id and published through Apogee. Like the first trilogy of episodes, "Secret of the Oracle" was released for free, and the other episode sold by Apogee. The game incorporates a more polished version of the graphical updates in ''Keen Dreams'', along with further gameplay changes and additions.<ref name="MOD7786"/>
* '''''[[Commander Keen in Aliens Ate My Babysitter]]''''' is the final id-developed game, released in December 1991 for MS-DOS. Originally planned to be the third episode of ''Goodbye, Galaxy'' and sixth episode overall, it was changed before development began to be a stand-alone game—stylized as ''Commander Keen in Aliens Ate My Babysitter!''—published as a retail title through [[FormGen]]. Due to differing timelines between FormGen and Apogee, despite being numbered as the sixth episode it was developed in between the fourth and fifth; it also features a modified engine from ''Goodbye, Galaxy''.<ref name="MOD7786"/><ref name="3DRretro"/>
* '''''[[Commander Keen (video game)|Commander Keen]]''''' was released on May 29, 2001, for the [[Game Boy Color]]. Developed by David A. Palmer Productions and published by [[Activision]], it was created as both a sequel and homage to the series as a whole, and does not have an episode number.<ref name="GSannounce"/> Id was not a major partner in development, though it retained editorial control over the game, and Adrian Carmack contributed some artwork. The idea for a Game Boy Color ''Keen'' game came from John Carmack and id, who approached Activision, which in turn proposed Palmer as the developer.<ref name="IGNrumor"/><ref name="IGNint"/>

===Cancelled and compilation releases===
After the release of ''Goodbye, Galaxy'' and ''Aliens Ate My Babysitter'' in 1991, id Software planned to make a third set of episodes for the following December, titled ''Commander Keen in The Universe is Toast!''. Beyond the proposed title and release date, shown in the epilogue of the two games, no design work was completed before the game was cancelled due to the success of id's ''[[Wolfenstein 3D]]'' (1992) and development focus on 3D [[first-person shooter]]s such as ''[[Doom (1993 video game)|Doom]]'' (1993).<ref name="3DRretro"/> John Carmack noted in 1999, when referencing the project that became the Game Boy Color game, that the original developers of ''Keen'' were unlikely to ever work together again on another game.<ref name="IGNrumor"/>

In 2019, at [[Bethesda Softworks|Bethesda's]] [[E3 2019|E3]] conference for iOS and Android devices held in June, a new game in the series was announced, again titled ''Commander Keen''. Under development by ZeniMax Online Studios, the mobile game was said to include tactical strategy elements and have both single-player and multiplayer gameplay, and star Keen's twin son and daughter, Billy and Billie. It was planned for release in the summer of the same year, but no release or further announcements were made, and all references to the game were removed from Bethesda and ZeniMax websites by June 2020.<ref name="KeenAnnounce"/><ref name="CKcancelled"/>

In addition to the initial releases of the games, several compilation releases have been published: the ''id Anthology'' compilation in 1996, which includes all seven episodes developed by id or Ideas from the Deep; a compilation release by Apogee in 1998 of the five episodes of ''Invasion of the Vorticons'' and ''Goodbye, Galaxy''; and the ''3D Realms Anthology'' in 2014, which also includes ''Vorticons'' and ''Galaxy''.<ref name="Compilation1"/><ref name="Compilation2"/> The Apogee-published episodes have also been released for modern computers through a [[DOS]] emulator, and sold through [[Steam (service)|Steam]] since 2007 as the ''Commander Keen Complete Pack''.<ref name="Steam"/>