As I understand it, the regular version has the capability to go much, MUCH deeper into dark play (rape ete,) It also opens up the possibility of incest, although we have not yet met the MC's sister other than on social media (and flashbacks?) . In addition to the regular download, you will need to get the patch (also on opening page) and set some value to true.
Note: Since I play the vanilla version, all of the above information is from postings in this thread. If I have mis-stated any facts, I would appreciate being told, so that I can edit this post.
