In all honesty, the enormity of the Cosmic Era info that you have produced is very daunting to me, and its why I dont always comment and vote on some of it: I feel like there is so much info I have missed and my comments and votes could end up being mis-informed. Also, fantasy is more my realm than Sci fi, so that's another hurdle for me to jump. I do like to try and vote on I i can though because you've put a hell of a lot of effort into the Cosmic Era, and it deserves recognition for that alone.
The Doom Bestiary was good because Doom is a very nostalgic thing for me : I have fond memories of blasting down gains of hell and such with my brothers or friends via the old serial network :p so because Doom was familiar to be I felt more comfortable checking out that sub!
I would say that other nostalgic type things would have a similar effect on other people, so by all means, go foe it!
Perhaps you can port over some Privateer stuff; that was the one space flying game I used to love! :p