Really loved the story and characters and their voice acting was great. Bosses are cool and combat is fun but once you've figured out a move rotation you like there's not much to really make you wanna change your strategy. I don't really mind this, but could maybe make it kinda boring if you wanted to replay for achievements or whatever.
This isn't necessarily a con but it also doesn't really feel like a Final Fantasy game besides from having the Eikons and Chocobos, I didn't mind this but if you wanted a very FF feeling game you might be kinda meh on this.
I personally really enjoyed the sidequests too even if they weren't really 'much' (they were mostly just talking to a few NPCs or fighting a few enemies) just because they built on the world or added more story to some characters and I thought they were interesting.