| Commander Keen in Invasion of the Vorticons | |
|---|---|
 Title screen of "Marooned on Mars" | |
| Developer(s) | Ideas from the Deep |
| Publisher(s) | Apogee Software |
| Designer(s) | Tom Hall |
| Programmer(s) | |
| Artist(s) | Adrian Carmack |
| Series | Commander Keen |
| Platform(s) | |
| Release | December 14, 1990 |
| Genre(s) | Side-scrolling platformer |
| Mode(s) | Single-player |
Commander Keen in Invasion of the Vorticons is a three-part episodic side-scrolling platform video game developed by Ideas from the Deep (a precursor to id Software) and published by Apogee Software in 1990 for MS-DOS. It is the first set of episodes of the Commander Keen series. The game follows the titular Commander Keen, an eight-year-old child genius, as he retrieves the stolen parts of his spaceship from the cities of Mars, prevents a recently arrived alien mothership from destroying landmarks on Earth, and hunts down the leader of the aliens, the Grand Intellect, on the alien home planet. The three episodes feature Keen running, jumping, and shooting through various levels while opposed by aliens, robots, and other hazards.
In September 1990, John Carmack, while working at programming studio Softdisk, developed a way to implement smooth side-scrolling in video games on personal computers (PCs), which at the time was the province of dedicated home video game consoles. Carmack and his coworkers John Romero and Tom Hall, along with Jay Wilbur and Lane Roathe, developed a demo of a PC version of Super Mario Bros. 3, but failed to convince Nintendo to invest in a PC port of their game. Soon afterwards, however, they were approached by Scott Miller of Apogee Software to develop an original game to be published through the Apogee shareware model. Hall designed the three-part game, John Carmack and Romero programmed it, Wilbur managed the team, and artist Adrian Carmack helped later in development. The team worked continuously for almost three months on the game, working late into the night at the office at Softdisk and taking their work computers to John Carmack's home to continue developing it.
Released by Apogee in December 1990, the trilogy of episodes was an immediate success. Apogee, whose monthly sales had been around US$7,000, made US$30,000 on Commander Keen alone in the first two weeks and US$60,000 per month by June. The first royalty check convinced the development team, then known as Ideas from the Deep, to quit their jobs at Softdisk. The team founded id Software shortly thereafter and went on to produce another four episodes of the Commander Keen series over the next year. The trilogy was lauded by reviewers due to the graphical achievement and humorous style, and id Software went on to develop other successful games, including Wolfenstein 3D (1992) and Doom (1993). The Vorticons trilogy has been released as part of several collections by id and Apogee since its first release, and has been sold for modern computers through Steam since 2007.