There are just two small things that bug me a little.
When walking on lava, you get a splashing sound, as if crossing a fresh stream.
Tree stumps (that can yield loot) spawn everywhere. Including underground.
I made a bit of fanfiction in my head about it, so jarring it felt to me : the cult of C’Thon actually grows trees underground BY FERTILIZING THEM WITH BLOOD ! These trees are the VEGETAL FOLLOWERS OF C’THON ! Obviously the Blood Grove is made of those.
Not to be confused with the plant enemies in Gloomwald and Ugdenbog, which are obviously followers of Wendigo