I played a game as the Harappans, Maya, and then Norse. I really enjoyed it! 

Questions I have: 

1. Notifications: The "curiosity" notification is still useless as it doesn't tell me what resource I acquired from discovering Animal Carcasses or whatnot, I have to hope that my screen is hovering over the unit as it makes the discovery, and then see the flash of "+10 gold" on the map before it disappears. These were also too same-y, I got what felt like 15 animal carcasses. Maybe spice them up with some variety. On that same note, the "Food" curiosities in the Neolithic could use some more variety, just a couple words of what they're eating, like "Blackberrys, Lychee harvested, Walnuts gathered, Cassava harvested", something to give a little more flavor and help me care about them a little more. 

2. Holy Sites: where does it say what my current count is, i.e. how many have I built out of how many my limit is. Suddenly the option disappeared, and had I known I was that close to my limit I might have saved a couple for my newer cities. 

3. Religion Bonuses: I chose some that gave me +1 science per worldwide follower of my religion, and that meant by the end that each holy site was giving me game-breaking amounts of science, over 220 per holy site, and that was just me playing through the Medieval era. Building a research district for a grand +10 science felt useless compared to my whopping amounts of science from my religion. It dwarfed the other option I could have chosen, +10 science per site or something. Similarly one religion bonus gave my capital +650 stability, which also felt overblown.
3. Faith...what does it actually do? I could see options of getting more faith from holy sites, wonders, the holy day festival, etc., but I didn't see any tutorial popup or any indication of what my faith was doing, and what producing more of it would do. 

4. Irreligious Civic--I got the option in the classical age and it was so awful I reloaded my save. It erased my whole religion and all of its bonuses, which were huge (see above point about holy sites) with no indication that this would happen. Since religion is so powerful, what is the point of this option. I really like the societal choice, but in terms of gameplay it didn't make much sense for me to ever choose it. 

5. Religion--is Tier IV it? I reached it in the Medieval era and then...there's nothing else for me to do with my religion? Can I evolve it some more or make more choices, or is that mechanic exhausted by the Medieval-ish age? 
6. What significance does the "attitude change" of a rival have? All of mine went from suspicious to afraid to reverential, but I couldn't see what effect that was actually having on my diplomacy. 

7. Diplomacy: what does "cultural agreement" mean? Does it actually change where I am on the civics meters, or does it just make our two nations like each others cultures more? I couldn't see any information about what it does. 

8. Can I still build unique units after I have evolved on from that culture? In particular, do the langskips stay my naval transport even after I move on from the Norse? 
9. Norse harbors--harbors can only be built once per territory, and indeed when I became Norse all my new territories could only build one Norse harbor. BUT, on my territories which ALREADY had a normal harbor, I could now build a second harbor, the unique Norse one. Does this deliberately overpower choosing a nation with a unique harbor? I could build a normal one, become Carthaginian and get one of theirs (right? I didn't play them), then become Norse and get one of theirs, so 3 total harbors on one territory? 

10. If City A, B, and C send their production to build a holy site (or other shared project) on City D, once it's built does City D then retain the overflow, leftover production? 

11. When I became Norse, all the men in my armies became Norse-looking, but still dressed up and painted as Mayans since that's when I built the unit. It felt a little culturally appropriative to see white guys in Mayan warpaint and dress. I do love that each unit has a different skin depending on the culture building it, that's really nice. 

I had a great time playing. I loved the hunting in the Neolithic, I loved founding and adding to my cities, I loved the ability of the Mayans to change their whole city's science and money to production as that helped me build all the Age I and II buildings pronto, I loved finally being able to cross the oceans as the Norse and found new settlements on an undiscovered continent. It feels great. I would love more STORIES!! More events, more narrative depth, more random events, I love that element of being immersed in my empire.