Well I suspect Voice acting would be a very expensive proposition and also not feasible for multi language support. So I wouldn't expect anything more than sound effects, grunting, groaning and perhaps some squirty sounds! (LOL)I only brought up Honey Select because they use the same engine. I really like the Unreal Engine as well, I think someone just came out with a new game using Unreal called "Wild Life".
I don't know if I am as interested in the audio for The Twist, as I am cleaning up the visuals. Do you know if he is thinking about adding Voice Acting?, or is it just going to be a bunch of Sound affects and Music?
I'm not sure he is using the Unreal Engine, I know he is using Unity (perhaps that is the Unreal Engine?)
The differences could just be the Rendering capability he has available...
IMO what makes this game so great is the story and content which really gets what the Incest genre is about.
Where other use tricks and subversion like Magic Powers or Blackmail...
This game is largely about the slow and subtle seduction that is the true exciting part about the Genre...
The anticipation, the caution needed to push the boundaries but not go too far to slowly get your target to open up and agree to your advances.
It's that RIGHT Incest tone that the Twist (and games like Dreaming of Dana) get right about the Genre.
And games like Big Brother sorely lack.
Not that those games are not good or fun to play it's just that they tend to miss the true joy of the Incest Genre and thats mostly because the developers don't really understand it. (which is normal not everyone gets the Genre)