Just beat the story, not to collect all the fragments.
Taking something from the other thread but couldn't reply to it there because of spoilers
Excluding story stuff (and even then mainly just execution related points), the only real complain I could think of was the quality of the animations for the real time cutscenes, which sometimes look a little stiff and not very fluid
I noticed this as well. Not just the fluidity, but also what they do. XIII-2 a lot of the cutscenes are sitting and talking, and while they have a lot of that in XIII- they are also more directed and doing stuff, like crying, or falling to the ground, or falling asleep next to each other, or hugging each other. In XIII-2 it really is them just standing around looking perplexed in cutscenes (with the beginning and the last chapter being the most well animated out of all of them).
But I actually don't think that's a bad thing because it makes sense. XIII is very story controlled, in XIII-2 there's a lot less story in just cutscenes and have dialogue inside in game conversations Also there are dialogue scenes that are for side quests so it won't be as well animated.
The only time I had an issue with it is during Noel's dream sequence in the Undying World. Which is sad, because that scene is the new Oerba for me, a beautiful haunting and imaginative scenery that just being in tells more of a story than any cutscene could ever do. I mean, none of the image changes were exactly innovative, but it was a fascinating place, how they up-ed the saturation on the red and dulled everything else, the red sky, and spot lights following Noel and Serah. And the fact that you had to unparadox the people around and then they would die, it kind of reminded me of the dream sequence in Heavy Rain where all the people fell down if you touched them. Just a really nice touch.
But the scenes between Noel and Caius looked so robotic. It was awkward to watch. And that's a shame because it was Noel and Caius's backstory and it deserved more love. And I couldn't help but notice that all the paradox people were the exact same models. It was like they had this great ambitious idea for this moment and then had to rush through it and do it sloppily.
I noticed I gripe a lot but more out of love than anything. I had so much fun with this game.