The plot reads like fanfiction, Stagger and the fact that your roles are still actually supposed to align with Commando, Ravager, and Medic/Sentinel is never explained at all unless you recognized their little symbols, and Lightning remains as dull as ever, the whole thing is a goddamned mess. But it's also really, really fun.
This isn't even a Final Fantasy game, this is a Tri-Ace game, and I mean that in a really good way. Combat is 13's fully realized final hour where everything is open to you, except it's all open to you from the very start. The time management makes things feel very fraught and like you're always on the brink of not making it to the next bit but in actuality you can just come back again another day which is a plus or minus depending on how you take it. Further, time doesn't pass in combat. For whatever reason I also liked how the apathetic populace typical of a sidequest heavy rpg actually comes into play into the plot, and it changes the world around you as you complete their quests. The people are 500+ years old and are just... done. They don't care anymore and are just waiting for the world to end, but when you help them you bring back meaning fulfillment to their life and they and the people around them change with it. Yusnaan goes from a mindless party awaiting the end to everyone helping each other out and preparing for what's to come, the air of desperation turns to one of actual enjoyment.
You don't level up, instead you get stat upgrades from completing quests so grinding is a non-issue unless you want to go about making the monster population extinct to get the "Last One" bonus rewards like an incredibly powerful sword and chips to level up your abilities. But the largest monster populations, for things that you can kill in one or two hits, aren't much above 100.
I couldn't in good conscience recommend anyone to go out and buy the game at full price, because as I said it's a mess, but it's also by and away the best entry in the FF13 trio. Probably because it doesn't feel like it was meant to be, it just happens to have the cast in it.