While I like the liveliness of Civ VI's game world (esp animations), the overall look of the UI and icons is definitely reminiscent of a plastic-heavy graphic look that Facebook games and their woeful ilk prefer. And don't get me started on the leaderscreens--the dreadful messy gloom of most (albeit not all) of the leaderscreen backgrounds makes it feel almost like a satire or unfinished prototype. And some leaders, like Alexander, look like plastic too. I don't mind stylized looks (I loved Civ IV's leaders), but I resent how cartoony some are in VI (Pedro, Victoria, Alexander etc) compared to others (Cyrus, Poundmaker, etc). The inconsistency rankles all the more when you notice things like Tamar's out-of-proportion hand size or Pericles' ridiculous helmet (not at all like his real life bust and more like a cartoon Solon).
Gameplay wise diplomacy and AI still have a long way to go before they become as threatening as the Civ IV AI (whose might makes diplomacy much more valuable).
I'm hopeful that the second expansion will improve diplomacy somewhat, but doubt we will get to the Civ IV sweet spot where each turn had so much excitement and depth, even for peaceful builders or those who already conquered most of the world.
Civ IV had diplomatic victory, vassals, random event quests, numerous complex trade deals with AI (not just for techs), complex AI diplomacy dealings (both more predictable and differentiated than Civ VI's haphazard "ignore past events and friendships and denounce all as warmongers" AI). Oh well.
I hope VI might introduce some new features we haven't seen before or at least in a while--an economic victory of some sort for example--the much reviled Civ Revolution had it, and the board game had a fairly ingenious economic victory as well.
