I finished Fire Emblem Fates: Conquest. My thoughts on the game are mixed.
Like everyone else, I think it's a ripoff move that they split Fire Emblem Fates into two separate games. I got cynical when they put emphasis on the playable characters from the other game, because that felt like blatant advertisement. Like, I'm playing Conquest; do I really need to see multiple cutscenes of Birthright characters?
I liked the battles, which were mostly good! They had good ideas and a nice amount of variation. But some battles I did not like: the two battles with a turn limit, and the one battle where two new enemies appeared every single turn. I understand that they were trying to make the game as hard as possible, but at those points, the line between "fun challenge" and "unfair challenge" is a bit blurry. You definitely need to play through on Easy Mode first, before you can conceivably beat the game on Normal Mode. Some challenges, you'll have to prepare for well in advance.
So, 90% of the time, I liked the battles. I also liked the marriage and children system in this game. Is it bad for me to say that some of the children are more interesting / better than their parents? Because some of those secondary characters were better than the main characters they spun off of.
Before the game's release, there was some backlash against censorship, with the romance scenes, where your main character invites romantic interests to their house for private visits. Even though we don't have the full versions of those scenes, they still come across as kind of weird and creepy. I would have preferred them to cut those scenes completely. I felt like a pervert, when the game forced me to blow into the microphone, to blow on my romantic interest. Also, the camera in these scenes scrolls down, to show off characters' chests. Even if you are talking to one of those kid characters, it will scroll down on them. I'm not sure what this is doing in a strategy game.
The thing I didn't like about the game was the story. The same basic story ideas repeated, over and over again. King Garron keeps sending Corrin on suicide missions, in hopes of killing her. Iago keeps forcing her to fight her biological family, in hopes of turning her evil. And every time Corrin makes a truce with someone to end the fighting, Hans shows up and starts killing innocent people to restart the bloodshed. Each of those three stories repeated at least four times, with little variation. Eventually, I had to wonder why my main characters were still putting up with these villains. If they had stopped the villains the first or second time, that would have saved a lot of grief.
Overall, I liked the game. It's not my favorite game in the series, but it's also not my least favorite. I think I would have enjoyed it a lot more, if they hadn't split the game in half.