The code for The Citadel was developed almost entirely on paper, as the author had been attending university at that time and only had access to his Atari on holidays. The hardest part of this pre-development were the puzzles, as only by playing through them the author could assess their difficulty and solvability. For this purpose, the author developed a crude version of the game on his girlfriend's ZX Spectrum computer during a stay with her family.
A sequel-in-spirit, named Orson, was released later on, as a result of the author's drive to create something with more "sexiness" than The Citadel. A proper sequel, Citadel II, was also in plans; it would have a greater variety and creativity in its design. However, it was discontinued while still in design phase due to the demise of the 8-bit Atari market. Add