If there are two things I like most in horror, they are:
(1) Nightmare edifices.
(2) Unspeakably grotesque monsters.
This story did the nightmare edifice justice, with a wonderful fake background story and a compelling image. The story reminded me of the Victorian Age idea of "influencing machines" (particularly the "Air Loom") in the way the Citadel had a strange, remote hold over the protagonist.
Likewise, I appreciated the message: stop fretting and analyzing your life, or you'll never live. A good message about overcoming the fear of death. Something we should all take to heart.
All that being said, there were some parts that I didn't like: the fear of death alone providing the motivating force made this story heavy on imagery, but light on plot. A more direct source of tension, such as inheriting the same disease as his father, might have helped. I also thought the comic book scenes made the story goofy and undermined, rather than illuminated it.
An okay piece, but not great.