Commander Keen Episode 1: Marooned on Mars

Commander Keen Episode 1: Marooned on Mars
Also known as: Commander Keen: Marooned on Mars Developer: id Software Publisher: Apogee Software Platform: DOS Released internationally: December 14, 1990 This game has unused graphics.

The first episode of the "Invasion of the Vorticons" trilogy, the first Commander Keen game, and the first game that iD Software released. It was also a success for both future FPS developer iD and shareware distributor Apogee.

Unused Graphic

This graphic is hidden in both Keen 1 and Keen 2, but it isn't used in either of those games. The letter "V" from the Standard Galatic Alphabet is on the card, so it would presumably be related to the Vorticons. It might have been a keycard that would have opened up any door.

(Source: Shikadi - Keen Wiki)