Commander Keen is an episodic video game 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 secret identity of "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 they were some of the first games by id Software (who went on to later develop Wolfenstein 3D, 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 game engine, which first allowed smooth side scrollers on PC by only redrawing the elements of the screen that actually changed frame to frame. 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. Commander Keen Complete Pack, a collection of the official Commander Keen games (excluding Aliens Ate My Baby Sitter! and Keen Dreams) was made available on Steam on August 3, 2007. Keen Dreams was ported and released for Android enabled devices on June 10, 2013 on Google Play. On October 23, 2014, 3D Realms released 3D Realms Anthology, which included Commander Keen: Goodbye Galaxy and Commander Keen: Invasion of the Vorticons in the collection.