Hello, Drednex. Thanks for checking out the game. The incest fetish is not a huge part of the experience, but it's in there. In particular, the potential for it ties in with the latter portion of the main story, the end game events that start launching after the main story completes, and there's also a handful of side story events that can occur w/ romantic interests in the game that also make mention of incest elements. Although, for those not interested in the fetish, all of these elements are purely optional.