Ahh, I think I found the problem!
I have a sex count tracker in place, but one or two of the events weren't actually adding to it, so it likely wasn't tracking your progress. Sorry about that, but thanks for bringing it to my attention! I'll definitely have that fixed for the next update.
Slight spoilers for the Return to Diadem XII endings below!!
As for endings, there are three variants of the Return to Diadem XII ending and they're directly affected by a "Fertility Point" tracking system I use; using probes and having sex increase the number of Fertility Points you get. Probes each give one, and you one FP per human you manage to seduce. Nine or fewer FP gives you the Soldier ending, Seventeen or fewer gives you the Retirement ending, and getting all Eighteen gives you the Demi-God ending! They're non-canon, and mostly just flavor text with different character graphics. Eventually I'll add a gallery system so people can see them after the canon ending.