Ok, so you never really complete a game like this. But I decided that, for now, I'd do one campaign and then move on to the next game.
So when I started I decided my first playthrough of this game would be on the easiest difficulty. I always do that with a new game. And then I decided to have a random leader since I didn't have a preference. I ended up with Russia, and the relationships and religions that followed through the game made me laugh a lot.
My first city started on a tundra landscape, which fits Russia. But then Kongo was my closest neighbour in the desert :P And a bit further from them were the Aztecs. The other countries were Brazil, Spain, Japan, Rome and Greece. When organised religion came about everything was hilarious. I made Russia buddhistic, Rome was Jewish, Greece was Muslim, Spain was Catholic. Japan was extremely devoted to Confucianism, and at one point scared the shit out of me. At one point I was vying for a religious victory, sending out apostles and missionaries all over the world, and then suddenly Japan shows up with a whole fleet of them right around my capital. I had no choice but to declare war against Japan and send out my military to massacre all the priests.
I don't do wars in Civ. I like to build and explore in Civ. If I want to conquer the world I play Total War. So as soon as I got rid of all the priests on my land, I simply let it become a ceasefire until Japan offered to make peace. And then I continued to sit back and grow in peace while my neighbours kept fighting each other :P
About round 300 I decided to focus on a science victory. That was closest to where I was going anyway. Building the spaceport and landing a man on the moon felt incredible, and finally, finally I founded a Mars colony and won the game, with less than 50 rounds left until the campaign would've ended automatically.
I know a lot of people compare Civ VI with Civ V, but I didn't play Civ V enough to be able to compare them fairly. All I know is that I thoroughly enjoyed Civ VI and I really want to play again.
Maybe not a theocratic, buddhistic Russia the next time?