First of, I love the game, it was a great experience and I had lots of fun all the way through. I played 140ish turns in one sitting, and ended the game unexpectedly by advancing to the industrial era which apparently wins the game. I was planning on trying to circumnavigate the world in the final 10 turns which almost worked but because of the sudden ending I couldn't complete that.

I could have opened a savegame but since it was already like 5 am I just went to bed instead.

What I liked the most:

1. The diplomacy system. I like how grievance build and can be forgiven or pushed, and how they may lead to war and other consequences, it feels pretty natural, and you can really choose to be forgiving or a bully. It may need a few more options (such as an ongoing payment per turn for some agreements) but overall it is great.
2. Terrain. I like how the terrain has different levels instead of generic "hills" and "high ground", high ground is context depended, which feels really natural. Cliffs and rivers feel great too, it brings a lot of thought into traversing terrain. It's not always well communicated where you can walk, the cliffs especially aren't always very obvious, maybe some tactical map overlay would help to make terrain a bit more clear.
3. The nomadic phase. It's really a fun way to start the game, explore your surroundings, get some fame points, and this phase already has a lot of options. 
4. The build-your-own-civ mechanic. Choosing civs every era gives you a lot of choice and ability to adapt depending on how the game turns out.

There is a problem with FoW where you can see enemy presence by trying to move over unseen terrain. I have never met that tribe, and my unit wasn't even close. But when I moved my mouse over there, it shows a battle preview despite not having vision or knowledge of the units/tribe there.

High yields don't sow properly, as there isn't enough space to display 3 digit numbers and the numbers overlap with the icon. It aqlmost looks like a yield of 10, but it's in fact 106

Pressing Q without a unit selected doesn't select a unit.

Overall a really fun experience. I started my run with kind of bullying another tribe. I discovered a natural wonder, and they claimed it (it was their second claimed territory, I was still completely nomadic, 0 territories), I demanded it, and to my surprise I got it. After that we kept having tensions between us, so at some point I made an army and crushed them and vassalized them. From there on it was pretty easy.