When it comes to porngames, story themes and writing are what pull you in and immerse you. Throw in decent visuals, and there aren’t all that many games left that click with me. Solid gameplay is a huge plus, but sometimes your options are just slim pickings.
Artificial intelligence is not yet mature, at least not yet, but it is developing rapidly. Once everything stabilizes, someone will certainly develop uncensored AI pornography models.
It must be an open-world game, and secondly, the NPCs must be bound to AI, with their dialogue and actions entirely determined by how you interact with the AI.