I never had it happen, but it was mentioned in the strategy guide.

In one of the battles in the prologue, if Hiro and old man whats-his-face die in certain positions, they'll actually block the boss from reaching the AI-controlled Lucia, effectively locking the game. In the U.S. version, if this happens, Ruby (the adorable little cat/dragon/mascot) kills the boss herself, and winds up pretty freaked out by her inexplicable show of awesome power. (Consider it a foreshadowing of things to come.)

I'm surprised how many don't mind the original game being changed significantly along with the translation. \

I think a translation should never alter a game apart from the translation and things like adding VWF and ROM expansion hacks to fit in the translated text.

But if you must, just add your hack as a second IPS to the translation, that way everybody can pick his favorite flavor.

Like I said: "within reason". My work on Sylvanian Families 1 removes the Flower Dictionary in favor of a different set of prizes for Emma's flower-growing minigame, and I had a neat little cheat in mind for allowing names of any length in Bistro Recipe: a dictionary scheme. Default names can be any length, player-created names can be at max 6 characters as per the original. I even managed to add an extra dialogue box where you're asked if you want to give a Foodon a special name.

What if it's intended to be unplayable?

OK that's a bit drastic, but you need to take care that by the hacks the game doesn't become too easy either. Note that this might differ with different people and generations.

I don't think there are any notable FF5A and FF6A bugs, although it shouldn't surprise me if there was a 1.1 revision of them all. I do believe there is major one for FF6A though.

Here's the funny, sad, strange story of the Anthologies version of FFV.

First off: FFV was once scheduled for a U.S. release. Twice, in fact. The first time was under the title of "Final Fantasy III", until it was pushed aside in favor of Final Fantasy VI, and the second time was as the PC title "Final Fantasy Extreme".

Square outsourced the development and localization of Final Fantasy V as Final Fantasy Extreme to another company. However, Square pulled the plug on the project before its completion, and its half-finished translation was left to molder until people started pestering Square to rectify its previous mistakes by releasing the PS1 ports of the SNES-generation Final Fantasies in the United States. It took a fair bit more pestering to get Final Fantasy IV out of the deal (which was later released with the unplayable PS1 version of Chrono Trigger in "Final Fantasy Chronicles"), but V and VI came to the U.S. as "Final Fantasy Anthology", featuring Woolsey's translation of Final Fantasy VI with the original Japanese title screen and all the PS1 version's goodies, and...the aborted Extreme translation of Final Fantasy V, rushed to gruesome completion. So not only is the game full of romanization errors and most of the nomenclature differs bizarrely from the rest of the canon translations ("Esna"?), but the translation itself was done half-and-half by two groups of people who had no input on each other's work.

...Thankfully, FFVA rectified all the obvious problems with FFV's infamous original translation, although I nonetheless find it curious that while both FFV and the near simultaneously-released FFXII use the original "Libra" for the ability previously known as "Scan", they went with "Exdeath" instead of the more consistent "Exodus" (which is still more appropriate than "X-Death").

That's one of my favorite things about FFXII...five of the Espers (an FFVI reference that was not actually in the original, although "Maseki"/"Magicite" does indeed appear in both) are named for classic Final Fantasy final bosses: Chaos, Mateus (the Emperor), Famfrit (the Cloud of Darkness), Zeromus and Exodus. Six more are the Zodiac Beasts from FFT: Belias, Cuchulainn, Adrammelech, Zalera, Hashmal and Ultima. And the twelfth...well, Shemhazai's all-original. ^_^

Actually, they're not two different names/characters/whatever. They're the same. Yes, they're spelled differently between the two versions in English, but they're the same name in Japanese. While I can see how the FFV people came up with ExDeath/X-Death the first time, I have to give this one to Exodus. Why the GBA version of FFV didn't use it is beyond me.