I'm currently working on an adult game based on the RPG Maker MV engine, with a lot of adult and non-adult artwork which I create in DAZ Studio. The game is called Peasant's Quest and is set in a medieval fantasy world, where you play a young farmboy out to seek adventure, and perhaps meet a few hot damsels in distress along the way.
My goal is to create a somewhat sand box type of game by making most of the quests/stories non-linear. You will (eventually) be able to meet and interact with many different NPC's and form a relationship with them based on the way you treat them.
Although there will be plenty of sexual materials, I also aim to make the game enjoyable as an RPG game in it's own right with plenty of puzzles and character building opportunities.