So the game is designed as a simulation so I would make a pregnancy mechanic by adding some rules.
If you have the time what in particular would need to be in a pregnancy mechanic and would would be "nice to have". Should it be realistic? Does breeding need to be profitable or is it ok as a money sink?
How I see the mechanic is this:
-To become pregnant a character must have a vagina and ovaries and to create pregnancy a character must have balls and a penis.
-Pregnancy occurs when the penis character climaxes inside the ovaries having character's vagina
-Pregnancy progress increases over time lasting around 9 in game months (I think a drug that increases progress speed would be good)
-Pregnant characters lactate milk
Now as a mechanic the main part I'm not sure about is the child, in free cities has the Incubation Facility which for a massive investment can speed up aging, eventually to 1 week = 1 year, this mean that the children can become full adult slaves in a not too bad timeframe.
Good, I'm glad to see you have played Free Cities. (with pregmod I assume)
So basically any mechanic Free Cities has, you could rip off, and I wouldn't be mad. But, take that with a grain of salt, as I'm speaking for myself there, not your community as a whole...
That being said, the one thing I can state, that I think all of us can agree on is this:
"The main thing that Free Cities got right from the get go was, leaving the players ability to choose what content they did or didn't see, Intact!"
If you learn anything from Free Cities and PregMod, learn that. Choice is very important! It's why I played Free Cities, and PregMod is why I still play today. But there are some things you have to keep in mind when comparing FCPM to your game KCC.
FCPM:
Deals with the game in the time frame of weeks.
KCC:
Deals with the game in the time frame of seconds/ten minutes/hours.
I'm not saying that it's a bad thing, just pointing out a factor. I had made my original post before actually playing KCC, but now that I've played it I have some suggestions, especially if you plan on this game to be as good as, if not better than, FCPM.
My suggestions:
But this is all just my thoughts, some may see it differently.
Also, don't try doing everything all at once, watch for burn out, and don't be afraid to ask for help.
You've got a good base to build on, and at the risk of sounding all "If You Build It They will Come" like. If you take your time, do it right, and listen to your community as a Whole (not just one person/group of persons) you could have a really good game on your hands.
Just remember, it's Your Game, the choices of what goes in it Comes From You, and Your Skills. But, (and this is a Big BUT) help and suggestions are always good, and lets you know what need fixing, adding, removing, or tweaking.
Man I hate my Brain sometimes, After thought is a bitch like that:
Feel free to message me directly if you have any questions.