I shall discuss the Skyrust-Nocturne-Twilight series herein.
Why did you design new rules?
Because I knew there was more than one system out there, I knew they had different feels, and I wanted one that felt more like mine. As time wore on, the design process morphed into a desire to create rules that felt like a story, and also had realism. Eventually, I did it because I wanted to finish what I'd started, and make it worthwhile compared to other things on the market.
How long did it take?
Probably about 10 years, so far. To break that down:
First 1-2 years: Skyrust system. Wanted to make something up. Did so. Made many mistakes. Learned.
Second period, ~5 years: Nocturne system. Tightened design focus onto realism. It got very bloated and rather odd. Eventually started cutting it back to a philosophy. Still required a calculator.
Third period, to present: Twilight system. Cut out the big numbers and shifted to dice pools as a continuation of the design philosophy. Recently rebuilt the skills to shift emphasis from combat onto other stuff. Very happy; possibly final form.
Did you ever want to publish it?
Oh yes. From my experience in other games, Twilight should offer something new and playable. Now I just have to find the time and inclination to finish it.
After Twilight's out, I'll develop a system currently codenamed Dawn. It'll be a great evolution, shifting from stat-driven play to scenario-driven play, with a heavily unified core mechanic. I'm quite excited about this, but I want to finish Twilight first, because that will be closer to peoples' expectations than Dawn.
Did you every actually run the System?
Skyrust and Nocturne, yes. Twilight, despite the fact that I'm super-proud of it, no. I will, one day. Oh yes, one day...
(This is where I recount the Funny Stories that spurred me to revise the system. Well, very briefly. Skyrust I tested the day after I wrote it, with a cousin of mine. Apparently, a supernatural power that says 'make it up and assign a reasonable cost' is unbalanced. Nocturne I tested more often, but the story that spurred the final philisophical revision is the Lycanthrope Incident, in which I learned that permanent powers are much more effective than instant powers, and that people don't like it when you beat them unconscious with their own arm.)
If you don't play it anymore why not?
Friends busy or busy with other systems. Myep. Must make time to playtest...
Was it specific to a Campaign world/genre/book series etc...?
Skyrust was specific, based on a story I half-wrote. Nocturne started off as an updated version of the engine based on an unwritten story based on the previous story, featuring a character named Nocturne. Twilight was just a name I liked, as it seemed a logical successor to Nocturne. I used the Twilight rules to build a crazy world where the rules were taken into account, thus coming full circle...
What's your Favorite Color....?
Red or field gray/green. Not blue. Blue sickens me - almost literally; I don't mind it, but people don't like me when I'm wearing it.