i forget what version is up as a demo here, but i'll give a go at answering you.

sex xp and good/ evil points are mostly uncompleted mechanics.  however, getting pregnant and giving birth provides you with a minion, the type is determined by what kind of monster did the impregnating.  parasite infection just gives birth to a weak monster.

the fountain on the game page is at the "hub" church you're at between runs, though i think that specific graphic of it is unique to the tutorial.