Computer gaming was truly hitting its stride for the first time in the early 1990s, and a large part of that wave of video games was the Commander Keen series. A colorful platforming series, the franchise starred a young boy as he took on an alter-ego in order to fight various invaders along with his rivals.

The series was produced by id Software, a company primarily known for its involvement in helping to create the first-person shooter genre of gaming with titles like Doom, Quake, and Wolfenstein. However, Commander Keen predated many of the titles that would define id Software. The Keen series got started when id co-founder John Carmack developed a trick for smooth-scrolling graphics in PC titles, and the programming team made a PC port of Super Mario Bros. 3. As Nintendo wasn’t interested in the PC market, the programmers at id instead partnered with Apogee to create Commander Keen.

The story arcs of Commander Keen are broken down into miniseries which are then further divided into episodes. The first story, Invasion of the Vorticons, consisted of three episodes, the second, Goodbye Galaxy, had two, and the final story, Aliens Ate My Baby Sitter!, had just one. There was also a “lost episode,” referred to as Keen Dreams, which is often referred to as episode 3.5.

The games follow Billy Blaze, an eight-year-old genius, who creates an interstellar starship from old soup cans. By donning a football helmet, he becomes Commander Keen to fight martians and other threats. His biggest threat is his rival, Mortimer McMire, who acts as the leader for a number of different alien races throughout the games.

Though the last Commander Keen game was a 2001 release for the Game Boy Color, the franchise had a huge impact on gaming at the time, particularly in regards to the smooth-scrolling graphics. Commander Keen himself has been referenced or seen in other id titles, such as Doom II, and Wolfenstein 3D. The helmet may have been put away, but in the 25 years since he first donned it, it’s clear that Commander Keen still has a presence in gaming today.