I remember you asked someone to completely take over making your storygame about a year ago, and just wondering...but is that what being your coauthor would entail?
If it is, I believe you should just give up. If you have no interest in making your own storygame, I think it's safe to say no one else would be either.
On the other hand, if you'd be willing to put in as much work into making your storygame as your coauthor, I would be interested in being your coauthor. I'm more of a proofreader than a writer, though.