So I've finally finished the game, clocking in at precisely 60 hours of gameplay. Finished about all the side quests, apart from two of the 3-star difficulty ones in the Dead Dunes; I assume they're currently impossible without NG+.
I actually finished everything on Day 9, then proceeded to do a lap around the world to buy new outfits and gear. Once that was done with, I pretty much put Lightning in a coma at the inn all the way to Day 13 lol.
Final boss was surprisingly easy. Not sure if it was just me being overpowered, but his first three forms didn't even require stagger to deal a considerable amount of damage. That being said, he at least offered some degree of challenge, unlike XIII-2's final boss.
My thoughts on the plot are that there isn't much of a plot. This is bad in one way, as it pretty much breaks the overarching flow of the storyline. It's actually a struggle at times to properly assess Lightning Returns' relation to the prequels. Square Enix went in a new direction with this third game, and I'm sure it must have caught a lot of people off guard. Simply not that much progression in the storyline. The plot's a mess, but that doesn't mean that the story itself is bad.
Here's how I see it. There are main quests which involve the cast of XIII, and there are side-quests whereby you entertain various NPCs. You solve their problems and, in the process, save their souls. The main quests are surprisingly short, and you'll find yourself spending a majority of your time on side quests. Main quests only serve as epilogues for the XIII characters. In fact, LR's story for the bulk of it is pretty much a compilation of epilogues for the various people you'll meet.
Each quest, both main and side, has its own unique storyline that I think is worth investing time in. You'll find that a lot of them serve to tell a story of how humans deal with death, but are still able to find some degree of hope amidst their despair. Of course, some are of rekindling relationships and finding hope in general, but I've discovered that a lot of the quests integrate death or loss of a loved one into their story. Both death and hope in the face of despair are recurring themes, and heck, Lightning pretty much shouts something similar to that in the ending. Even when there is death, ideas and memories live on through the rest of humanity. And those memories, of which evoke emotions such as hope, anger, love, sadness, and happiness, are what makes humanity strong. No matter what, humanity will continue to live on and find their way, through thick and thin. These are excellent morals, genuine morals that I rarely see in a video game story. Last one I played that actually did something as prominent was Persona 4, or perhaps Catherine. A lot of games tend to be morally ambiguous, and while that creates interesting conflict for plot, it's a nice change of pace when a game just there to instill positive ideas.
Being someone who has invested a lot of time into XIII and the Fabula Nova Crystallis mythology, as well as having an avid interest in literature, I actually found the story to be somewhat fitting. Yes, there's a lot of cheese, and on multiple occasions the narrative fails to explain things properly. Plot-wise, bad. Narrative-wise, confusing. But aside from those, the story isn't half as bad as people make it out to be. It's actually pretty heartfelt and clever.
As for gameplay, battle system is really fun. Square Enix took inspiration from the hack and slash genre of games and then sort of fit that into the typical XIII battle mechanics. Plenty of hidden mechanics and a multitude possibilities, which is what I've always enjoyed when playing through games like Bayonetta and Devil May Cry. From an RPG perspective, it's still pretty robust. You can still sort of grind your way to victory, and there are a lot of abilities, equipments, and stats for you to carefully customise. While skill does play a factor in battles now, the RPG factor is still key in deciding whether you win or lose a fight.
Exploration-wise, while I had fun managing time to finish up the quests the first time, I'm actually quite worried that I might not have the motivation for doing that again on NG+. Running around doing the same side quests and finding the same accessory locations feel a bit daunting. Not to mention exterminating monsters in order to make the Ultimate Lair much easier. It requires so much active participation, which would probably burn me out considering the amount of hours required for all that grinding.
Ended up writing more than I would've preferred lol. I liked the game, even if many don't. I just looked past the issues it has to find a few gems worth praising about. I am satisfied with this end to the XIII trilogy, and I'm proud to know I can justify my argument for liking it better than any hater could. It was a neat send-off, not just for Lightning, but for every other character and humanity itself.