Despite putting in at least an hour or two into it, the only real change in scenes I've seen so far is during an experimental run to see everything that could be offered, you basically have the option to rape some girl in like a white summer dress or something (I forget what she was wearing), with the option to back out of it if you want. Naturally, the scene paints you out as a creeper since your character just throws her down while she's all confused.
I don't remember if extreme violence was ever in the vanilla game, but if it wasn't, then the hgg mod added it, because I saw a womb fuck option for the goblin girl. And no, it's not one of those extreme penetrations either.