These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anticlimax Boss: The final form of Orphan is... less than impressive when compared to its monstrous and extremely powerful first form, arguably due to the absence of Barthandelus and its unintimidating voice. Nevertheless, it is still somewhat challenging, especially when compared to otherexamples.
Some fans see Lightning as a stoic, beautiful badass with a well-developed character, while others see her as a cold-hearted bitch who is never called out on her behavior and only gets a pass from the fans for it because she's attractive. And then there's fans who like her but wish Square-Enix would stop whoring her out in sequels and spin-offs — in her comparatively short existence, she's become the face of the Fabula Nova Crystallis universe, and has almost half a dozen cameos in other games as well.
Broken Base: The game itself, with many people who love it, but just as many who hate it, for various reasons.
Averted, however, by the lack of the traditional Final Fantasy victory fanfare, which is replaced by a very understated tune.
Disappointing Last Level: Completely Inverted, as the consensus is that the game is much much better when you get to chapter 11 (it's all linear up to that point). This was actually intended, as the developers stated that Cocoon was more story-driven whereas Pulse was more exploration-driven. (A lot of the people mostly complained about not getting to see more of Cocoon... and really, wouldn't YOU?)
Hope's mom Nora had a bigger impact on some players than most of the cast combined.
There are still people upset that Jihl didn't have a bigger role, especially since early trailers played her up as a major antagonist. Demands that she should have been faced in battle were also heard, and met with XIII-2 at least.
Everyone Is Jesus in Purgatory: Let's see, we'll start with the fal'Cie Anima (conveniently cross shaped) l'Cieifying everyone, then blowing up the Hanging Edge, and freezing Lake Bresha. Oh, and it's made of hundreds of church bells that ring while an opera sings a melancholy tune. And that's just the prologue.
Evil Is Sexy: Jihl Nabaat, a glass-wearing PSICOM officer with considerably assets.
Expy: The Eidolons are giant robotic humanoids who can convert into the forms of vehicles or robotic animals in their Gestalt Mode. Sound familiar?
"Funny Aneurysm" Moment: During the fireworks scene in Bodhum, Snow says to Serah, "Our engagement is way bigger news." When they do tell Lightning about Serah becoming a l'Cie and their engagement the next day, Lightning doesn't believe in them largely because of the engagement, thinking it's made up as an excuse so they can get married.
Some of the full ATB skills can be outright devastating if used properly. Lightning's Army of One seems to stand out among them due to how many things you can do to capitalize on its effectiveness.
While most buffs manage to be fairly useful, Haste stands out as being incomparably so, and will become a staple of every major battle you get in. Even better, the AI knows this, and AI Synergists will prioritize using Haste before all other buffs.
Les Yay: Fang and Vanille come very close to crossing the border between subtext and text. The ending practically makes it canon.
Like You Would Really Do It: Sazh apparently committing suicide, horrifyingly dramatic though it may be, is pretty obviously not going to stick since it comes directly after he obtains his eidolon.
Magnificent Bastard: Barthandelus may be one of the most guile and competent villains in the series. He manipulates everyone, Cocoon civilians, the Sanctum, PSICOM, other fal'Cie, and of course the party, in a plan spanning five centuries. And while the result wasn't what he wanted, his plan worked perfectly. He's so good that even when the party knows he's manipulating them and setting them up, they go along with it because they have no choice, he's forced their hand in some manner.
A series of Tumblr macros about the cast has produced "Vodka Lightning". The series has been noticed by Ali Hillis and Liam O'brien, who find them all hilarious, and even Ali agrees◊ with the captions on how sexy Liam's voice is.
Misblamed: Do the names Motomu Toriyama, Toshiro Tsuchida, or Yoshinori Kitase mean anything to you? Kitase is the producer of the game, as well as one of the designers. Toriyama is the director, and Tsuchida is another one of the game designers. But in the eyes of many critics, the designer, producer, publisher, debugger, marketer, and localizer was Tetsuya Nomura... who only is credited as one of the artists, and you know what else? He's not even the ART Director! Anyone who knows Tetsuya Nomura well enough to dislike him should be able to tell that this game isn't even really his style.
Barthandelus callously shattering the crystallized Dajh and Serah prior to the final confrontation has been met with similar revulsion. Granted, this was just an illusion, but still.
Jihl was already a manipulative bitch for taking away Dajh from Sazh for being a Cocoon L'Cie, and allowing PSICOM soldiers to open fire at Nautilus of all places. But then she manipulates Sazh into letting him kill Vanille because she was partially responsible for Dajh becoming a L'Cie in the first place. Her reaction? To sit back and watch, because she thinks it would be amusing to see one L'Cie kill another.
Orphan crosses it when he transforms the party into Cie'th.
Flanitors. Sirens are already annoying, but at least in real life they pass by and grow quiet. These, however, just don't stop until you kill them. And there are a LOT of them in the area. And they heal each other. While making noise!
The continuous alarm that blares while you're onboard the Palamecia and the only time it ceases is when you access the menu. Code Red, Code Green, Code Purple, whatever, fine, but somebody shut off that damn alarm!
That is one satisfying breaking sound every time Lightning finishes her gestalt with Zantetsuken. BAM-BAM-SMASSSSSHHHHH
Whenever you fill the stagger bar, particularly on a very resistant enemy.
No Yay: Just before their confrontation at Oerba, Dysley assumes the appearance of Serah and gives Snow a big hug. Pass the brain bleach, please.
Real Women Never Wear Dresses: Lighting has constantly praised for being a "strong" female character. The problem comes in that fans refer to the pre-development Lightning, who berates and belittles her companions. Yet, Serah, who is hands down more feminine than Light, has become almost a Scrappy to players for her "weak" personality.
The same person who decided that it'd be good to see all three characters randomly decide to strike a pose the first time you paradigm shift — without the battle pausing at all.
And probably also the same person who decided to leave party control entirely up to the AI. Apparently they weren't aware of how afflicted with micromanagitis some gamers are, and said gamers were quite insulted.
Squick: The Hope and Lightning Ship Tease is not very subtle and is sweet in some ways... a reminder though that Hope is 14, and a lot of the Ship Tease is Lightning acting as his Parental Substitute. Add in that "Nora" is the Greek word for "Light", and suddenly the Unfortunate Implications of a potential romance with them hits.
Surprise Difficulty: This is one of the handful of Final Fantasy games you can't load up your favorite characters with overpowered spells and weapons and blast through the game easily after a bit of Level Grinding. The usual Absurdly High Level Cap is avoided, with a cap on the Crystarium throughout the game that gets raised a bit higher at set points. This puts a limit on how strong your party can be at a given point, and even once you're allowed to begin training the party in all six roles, some are clearly better than others at set roles, and no one character is the best at everything. All in all, the game forces you to plan out your Paradigms, observe the flow of battle and switch Paradigms to react to enemy behavior, and know each party member's strengths and how to use them best.
Except with Death being a slap on the wrist, and the reset being a humble start-select button combination away, the combat becomes less of the above, and more of finding out the right answer to the puzzle. Making FFXIII feel more like a puzzle game than an RPG.
Barthandelus is quite a formidable opponent, particularly in his first and second incarnations. He has loads of HP and enjoys dropping a doom timer on your party leader, so your damage had better be top notch.
The battle with Cid Raines is a very difficult one at the time the player is required to fight them, especially since he's more than capable of taking out any unprepared player in one swoop, and can apparently cast the uncurable death countdown spell if the player takes too long to defeat him, ouch!
Each player seems to find at least one Eidolon battle to be a pain in the ass.
The True Final Boss's first form. He has the highest HP of any non-optional boss, causes tons of negative status effects, and has an attack that will always leave each of your non-Sentinel characters with less than 100 HP, unless your characters are poisoned, in which case they'll be dead before the attack animation is even finished. And if you're lucky enough to survive the phase of the battle where he causes all those status effects, he can still randomly and unpredictably cause instant death on any character, including your party leader, which means instant game over.
That One Level: Near the beginning of Chapter 4, when Lightning leaves the rest of you behind, you're assigned a party of 3 non-COMMANDO characters for a duration. This period can be the most annoying part of the game; without a COM in your party, enemies with high defense or hit points become Goddamned Bats, as killing these Mooks without the aid of Stagger (which COM characters are a vital asset for inflicting) becomes a marathon of sorts. Battles that normally take less than a minute can easily go past five in this part of the game. Fortunately, Sazh learns the COM class after this section is over, so the problem never arises again. As a light compensation, 2 of the 3 characters you do get have the MEDIC class, so death is rarely a threat for this section, and the game makes a point that here, rival groups of enemies will fight each other, allowing you more pre-emptive strike chances and to whittle down both groups as they focus on each other before turning to you.
Another potentially frustrating sidequest is getting the Treasure Hunter Trophy, which involves getting every weapon and accessory in the game (thankfully not all at once, just owning each one at some point in the playthrough is enough). It requires an unfathomable amount of cash to do since you need to do a lot of upgrading, plus you need to get at least six of the rare and expensive Trapazohedrons (although there's a trick that allows you to get by with only having to find/buy two). It's not exactly difficult to do, but it takes much longer than anything else in the game and demands that you spend many hours farming Oretoises and Sacrifices.
Many had hoped to see Jihl Nabaat as the main villain or at least an active one and was very disappointed to see her killed off after a total of ten minutes of screentime. So, not surprisingly, those same fans rejoiced in the sequel where, in one of the alternate timelines, you finally get the opportunity to give Jihl the sound thrashing that's been overdue for years.
Hope's Mother Nora is definitely this. Though one can argue her death is what serves as the basis for Hope's growth and storyline, her scenes in the beginning clearly paint her as this stronger-than-she-looks woman that's telling Snow "Mom's Are Tough" and she even saves his life. Then she's apparently fatally wounded by an inexplicable injury and plummets to her death whilst Snow survives the fall of the same altitude. She's not an Ensemble DarkHorse for nothing.
Wangst: Many players claim Hope is guilty of this. A vast majority of the players forget that Hope is only fourteen. Other people feel that Hope's reaction is perfectly justified as a character but are just annoyed at the writers for going down that predictable path, making it an out-of-universe Pet Peeve Trope. In addition, while it is completely justified in the game, it's still not something a player would like to endure in a video game, rather than a movie.
The Woobie: Pick a protagonist. Chances are, they'll each get at least one scene in this role. However, see Jerkass Woobie, too.
Serah ESPECIALLY. She gets killed to be turned into a McGuffin...TWICE!