This is going without saying:
More party banter/dialog.
Along that line: maybe have a "relationship" style quest w/ lots of dialog--not necessarily romantic in nature.
Awesome writhing too but no need to mention it, we will get it any way. What I would add is:
More reactivity, or better say - recognition. It's a bit immersion breaking when someone comments about let's say eyes, for example, of a death-god-like character without visible eyes.
More voices (while we are on characters)
Actually, it's sound like "more of the existing game features" and we will get it