I like this idea.
I'm writing a Zelda (OoT) fanfic. It's not rationalist fiction in the strictest sense, but playing things straight is one of the core ideas; as the mission statement on the first page says, it's partly about de-gamifying the game.
Comments are welcome on both the content and the presentation. As usual with these things, some knowledge of the original work and the surrounding fandom will be helpful.
I'd be happy to swap chapter-by-chapter critiques with you.
This community has a recurring interest in "rationalist fiction," and several members who are writers. I wonder if it would be useful to create a space where Less Wrong members could provide each other constructive criticism and encouragement on in-progress original writing projects?
Disclosure: I'm working on a sci-fi novel right now, and my regular circle of "beta readers" are fantasy fans and aren't providing much feedback on the new project. I am much, much more productive as a writer when I get steady feedback, so I have a personal interest in looking for something like this. Less Wrong came to mind as a community of intelligent, creative, forward-looking types who are likely to enjoy sci-fi.