WHAT SUPPORTS THIS RUMOR:
Originally there was a rumor spread by a certain individual named Ben Lansing who claimed that Square had originally been working on a scenario which, if completed, would allow you to bring Aerith back to life using a special materia. The reason why people thought he had so much credibility is because he said he was a former temporary worker for Square USA, and the information he presented to the 'outside world' seemed impossible for someone to know unless they had been affiliated with Square.
In the game itself, there is an Independent Materia called 'Suichuu Kokyuu' which means 'Underwater Breath/Respiration'. You can only get it using a Game Shark code. According to Mr. Lansing's story, you needed a materia that would let you go underwater in order to revive Aerith, so this could be that materia that he was referring to, since there are no other materia in the game with that name or power. Also, if you return to Midgar City in Disc 2 or 3, you will see a flickering image of Aerith in the church that Mr. Lansing claimed was left in by mistake--it was supposed to be followed by a sequence with Cloud talking to Aerith's ghost. Lansing also gave several reasons for Square removing the revival process, including the fact that Square was pressed for time. This is true--Square had already delayed the game once and finished it shortly before it was shipped, and the obvious incompleteness of the ending adds even more credence to his story.
Also, before the final battle, there is an extra ledge that no one is standing on. And if you are able to make three groups, one group will only have two members. Some people say that that proves that there should have been an extra member in your party, who would be Aerith.
WHAT CONTRADICTS THIS RUMOR:
Mr. Lansing claimed that the materia that would let you go underwater was a yellow (Command) materia. The 'Suichuu Kokyuu' materia is purple (Independent) instead. Also, it has no known effect in the game, even if one has follows the instructions concerning the Materia that Lansing explained in his message. Furthermore, he claimed that there were two alternate endings you could see if Aerith was revived, but it has been proven that there are no extra FMV ending files on any of the discs, and even if the ending wasn't an FMV sequence, no one has yet discovered any of quotes or graphics that might have been used in either of the 'alternate' endings. Most people also overlook the fact that, although it's difficult, you CAN get her 4th level Limit Break before her death near the end of Disc One--it was originally thought that if you couldn't get it normally, why would it be in the game unless Aerith could get it after her revival? Now, of course, that has been proven to be false.
One part of Lansing's story is rather interesting since it has yet to be fully proven or disproved. To get the underwater breathing materia, according to him, you had to get the Area 5 Key during the first disc, take Aerith to meet the General, then go into Midgar City and meet the General's sick friend. Aerith would care for him, but he would still die. Because Aerith tried to help, the General would remember her and give Cloud the Suichuu Kokyuu materia in Disc 2. According to Lansing, the one thing that prevents you from doing this little side-quest is the Area 5 Key, which was removed in the first disc only. He insists that the quest could be partially completed with a Game Shark.
Now, you get the Area 5 Key by digging at the Excavator's Site. But you can't even dig at the site until after Aerith's left for the Ancient City. So you'd need two codes, one to be able to dig up the Key, and another one to stick Aerith back in your party (that last part is easy enough to do :)) Even assuming you had a GS code to simply put the Area 5 Key in your inventory, you'd run into another problem almost immediately: while you do see the General leaving the town after rescuing Aerith from the church in Midgar, he doesn't appear outside of the city until the second disc, which means that Lansing wasn't exactly right; _two_ things were removed from the game, if his story is true. And the General is a key part of this so-called sub-quest. That would seem to prove his story false right there, but the General didn't give the materia until after you had cared for his sick friend (the guy living in the tube near Aerith's house). If you were able to get back into Midgar with Aerith, and _anything_ happened when you met the sick man, that alone would be very important; according to Lansing, the whole point of this quest is to be able to revive Aerith later, so if it's in there, it may be for the reason he stated. And if the General appeared when you left and gave you the Underwater Breath materia or gave it to Cloud in Disc 2, as Lansing states, then that would be the first piece of hard evidence to come forward concerning the rumor.
The game's plot is also a large obstacle in the way of this rumor. While it seems that Square could have changed the plot in order to 'cover up' the removed revival process, that would be a lot of dialogue to change. Even the bit with Aerith in the church after her death is explained in the game. The biggest contradiction is that Aerith has NO lines of her own in any of the other discs, even if a Game Shark code is used to access her in later discs. Also, the game freezes if she enters any conversation/event in the later discs, further discrediting the rumor. The only times she speaks is when she's saying a quote that any character in your party would say at the time (such as just after crashing during the snowboard event). She also has no extra weapons available to her in later discs, unlike any other character.
MY OPINION:
No, you cannot revive Aerith. If you really have to play with her, just use my Game Shark code, okay? :)
WHAT SUPPORTS THIS RUMOR:
The fact that Sephiroth does join your party, at least for a time. Like any playable character, he can fight, cast magic, and even use magic outside of battle. Plus, you can move him around and check his stats. If you use a Game Shark code, you can unequip and equip him with materia and other equipment. As for Baakusa, he is supposed to be an imp (better known as a kappa to Japanese gamers) that was removed from the game due to time constraints, as the rumor goes. Using the same code that enables Sephiroth to join your party at any time, you can also see two extra character portraits, made up of red hiragana (characters used in the Japanese alphabet). One of those could belong to Baakusa. And Young Cloud has his own portrait, his own stats, and can use materia. He can equip things, raise levels, and be controlled in battle just like a normal ally. Throughout the game, Cloud battles his 'self'--that second self could be the younger part of him, or Young Cloud.
WHAT CONTRADICTS THIS RUMOR:
Even with Sephiroth in your party, he is still controlled by the computer. And like with the GS code that lets you use Aerith, Sephiroth cannot have a conversation or appear on the screen without the game hanging, indicating that he has no lines in the game, not even 'general quotes' that any ally might say. Furthermore, he has no weapons available to him aside from the Masamune (which doesn't even have it's own icon; see below), and his portrait cannot appear on the PHS screen. To add to that, Sephiroth does not have any Limit Breaks; if you use the GS code, it says that he has Vincent's, which is impossible*.
While one of the two portraits could conceivably be for Baakusa, the translations of the characters spell out 'Now Printing'. A likely conclusion for this would be that this was used while the portraits were still being drawn/decided upon, a theory that is further backed up by the fact that in the FF7 demo disc, none of the characters have the same portraits used in the finished version (in fact, Cloud has Young Cloud's portrait!) If you load up either of the 'Now Printing' portraits using a Game Shark code, you'll see that they don't have their own stats/limit break/etc. Also, each character in FF7 uses his own type of weapon, but Baakusa has none, while even Sephiroth had a weapon (although the icon with it was Vincent's gun, indicating that perhaps you would never be able to buy/receive new weapons for Seph, which further discredits that rumor). The 'Now Printing' portrait won't fit in the PHS screen, either.
How could Young Cloud join your party--through a time warp? Remember, Cloud's flashback takes place several years ago. Even if you could get Young Cloud, what would the point be? Young Cloud doesn't have a Limit Break; use a code and it says you have Cait Sith's (which is a bug since Young Cloud, like Sephiroth, can't use it, even if you activate a Game Shark code to have an fully-filled Limit Meter). And the Cloud in your party can do everything Young Cloud could do, too. He also starts at a higher level. Like the other 'hidden' characters, Young Cloud's portrait is messed up if you try to stick him in the PHS screen. So even if you could get Young Cloud, why would you want him? *
Vincent is NOT Sephiroth, despite what some people say. The only reason why Vincent and Seph seem to have some similar abilities in terms of 'glitch' weapons and 'glitch' Limit Breaks is because Vincent is considered by the game to be the last normal character in the game before Sephiroth. Although he comes before Cid in the 'Character Select' code, that's because the nine playable characters appear in the earliest order that you could receive them. In terms of Limit Breaks and weapons, Vincent always appears before Sephiroth, and the only reason why the handgun icon is used for Sephiroth's Masamune is because you're not able to equip Sephiroth with other weapons--the designers of the game had no need to make an icon because no one could ever see it normally, so they just used Vincent's. Even if you don't believe this, Vincent's past (he was a former Turk) goes against the plot--and Sephiroth was already alive at the time (in his human form...I'm not talking about the 'copy' Sephiroths that you see throughout the game. Sephiroth protects his body by placing it in the Crater, but before he learned that he was inhuman, he only used his real body). And no, I don't believe the theory that Seph could have controlled his alternate form of 'Vincent' by mind control, the same way that Reeve controls Cait Sith. If I got the plot confused--well, hey, I can't read any of it, so don't blame me.
MY OPINION:
Vincent and Yuffie are the only 'hidden' characters in the game--the only time when Sephiroth is in your party is during Cloud's flashback at Kalm Town in Disc 1 (when Cloud is replaced by Young Cloud), and there is no character named 'Baakusa'. Once again, if you just have to have either Seph or Young Cloud in your party, try a GS code.
WHAT SUPPORTS THIS RUMOR:
There is a chocobo 'portrait' in the game, just like the one that your allies have. Also, the chocobo isn't a true enemy in the game, he/she will only atack if you hit it first. Plus, you can ride around on them and breed them, so perhaps they're friendly enough to want to fight alongside your allies.
WHAT CONTRADICTS THIS RUMOR:
The portrait is used simply for the purpose of naming a Chocobo during the breeding scenario in Disc 2 onwards. Should you use a Game Shark code to add the portrait to your party, you'll see that it doesn't have it's own stats/limit breaks/etc, and the portrait glitches in the PHS menu. And, there are no weapons in the game made for a Chocobo to use. Most importantly, there isn't even a 'Chocobo Control' materia in the game, and you can't control Chocobos using 'Ayatsuru', either. Even if you could, you could probably only make them attack someone, not join your party. If they did have such a command, it would be the sole exception out of every other controlled monster's commands in the entire game.
MY OPINION:
There is no way to have a Chocobo join your party at any time during the game.
If you think about it, all these rumors contradict each other. There are nine spaces in the PHS screen, and supposing you could revive Aerith, they would all be filled. But, one character is always leading the party, so that clears up a space. None of the hidden characters portraits will work in the PHS screen. However, Cloud's portrait fits in the PHS screen, so that would leave three free spaces (your active party). So it must be possible, right? Wrong. There are four rumored characters: Sephiroth, Young Cloud, Baakusa, and the Chocobo. So where would the fourth one go? And if you say that they'd all fit if you couldn't revive Aerith, then, okay, you may be right--but that means that the rumor about bringing Aerith back to life is false, and if it's true, one of the above rumors is also false. If you say that maybe they only join for a little while (maybe while Cloud is recuperating in Mideel or for the period of time between Aerith's death and the first chance you would have to supposedly 'revive' her), then that would also be an event unlike any other event in the game. Sephiroth is only in your party for a little while, but remember that it's not really your current party--it's just Young Cloud and Sephiroth during Cloud's flashback.
WHAT SUPPORTS THIS RUMOR:
Frankly, most everyone agrees that the ending does seem a little incomplete. And Mr. Lansing said that the 'main' ending was supposed to have scenes with Vincent and Yuffie in it. In terms of FF7's plot, the ending seems to wrap up Cloud's history and his troubles, but you never hear about anyone else, with the exception of Red 13 (and that's not explained either). Taking the Aerith rumor into consideration, throughout the game, Cloud is in situations in which he either must pick Aerith over Tifa or show that he is a caring guy or an uncaring guy. But, these choices affect the game in a very minor manner--the characters reactions change a little, and the 'date' scene in the Gold Saucer changes depending on the choices you made, but after Disc 1, the whole thing is dropped. According to information concerning the other endings, Aerith lives happily with Cloud or commits suicide (read the Documents section below) because of Cloud's actions. Considering the number of times when Cloud, Tifa, and Aerith get involved in a situation like the ones I mentioned, it seems very likely that there could be other endings.
WHAT CONTRADICTS THIS RUMOR:
People have searched the third disc and have proven that there are no extra ending FMVs. Even if the endings didn't use FMV, this goes against the design of the main ending. And despite replaying the game, no one has yet found a significantly different path to take, (failing all 4 Huge Materia quests has virtually no effect on the game's course) nor have they found any other endings.
MY OPINION:
I hate to say it, but it seems that there's only one ending in the game. I think that there could have been other endings planned, though, even if they were never actually completed or put on the discs. I don't know if people have tried searching Disc 1 or 2 for the alternate endings, but it seems a little odd to have to switch to an earlier disc to see an ending sequence, so there may not be any endings on those discs, either.
WHAT SUPPORTS THIS RUMOR:
Just about everything :) There are disabled Materia in the game, unused portraits (albeit possible test portraits at that), a seemingly unfinished ending, and the fact that Disc 3 seems incredibly rushed, which would be likely considering that Square announced that FF7 would be a 3-disc game instead of a 2-disc game very late into their production of the RPG. There are many graphical glitches that could have been easily fixed (such as when you view most characters up close), and both the actual game itself and the mini-games could have used some play testing (as people and game reviewers have both said). One rather interesting point that no one has yet mentioned is that there are three spaces for each Limit Break level, both in the Main Menu sub-screens and on the red window that appears when you use a Limit Break in battle--it could be that characters were originally going to have extra Breaks, but this was dropped when the programmers began to run short on time.
WHAT CONTRADICTS THIS RUMOR:
Few games that are designed are ever released exactly the way they were thought up. This is due to a number of reasons; lack of money, time constraints (which Lansing hinted as being the biggest reason why Square may have cut things out of the game), or lack of interest from both the programmers and the consumers. FF7 is a complete game in terms of being able to play, understand, and beat it, so it was released in a 'usable' form. And even using GS codes, it has been discovered that there are no other Limit Breaks in the games aside from the ones your characters can normally get in the game.
MY OPINION:
Cuts in the game? Absolutely! Like I said above, not every game is released exactly the way it was intended to, but I think the main reason why everyone got ticked off about FF7 is because so much was removed at the last moment. There's only one ending on the disc, in my view. Does that mean that Square never planned any other endings? Of course not! In my honest opinion, I do think there were going to be more hidden characters, and I do think that Square may have toyed with the idea of being able to revive Aerith. Just because none of this is evident in the final version doesn't mean it never happened. FF7 was put together very hastily and it seems like the programmers may have changed their minds as to what works and what doesn't throughout the game. The 'Materia Select' code and the extra character portraits show that. Even if the portraits were just test images to be used before the real ones were put in, you think the programmers would clean things up and remove them before putting out the finished title. Same for the 'Active Battle' debugger that happens as a result of the Item Select Game Shark Code. And the sudden change from 2 discs to 3 before FF7 was released was also very convincing--there's only one new area on the third disc. Everything else, from the bonus areas to the Ultima Weapon, all show up first on the second disc. If you think about it even more, what's the difference between discs except for FMV? The 'FMV Viewing Trick' proves that ALL the discs have the same program on them; I played through several areas of each disc that would seem specific to that disc with another FF CD in the PlayStation, and they all loaded and played (like the snowboard and submarine sequences, which aren't available in Disc 1, or the whole first few hours of the game, which can't be reached in Disc 2 or 3 since Area 7 of Midgar City is destroyed early on in Disc 1.) The only difference between Disc 1 and 2, and 3 are the FMV files, but all the discs have at least some of the same FMV on them (the lift in Junon Town, the observatory in Cosmo Canyon, and the sky lift going to and from the Gold Saucer are on all three discs, and the bit with the rotating silver car can be found on Discs 1 and 3, at the least). So yeah, I'd say that FF7 definitely has had some parts that were not implemented and/or cut out for various reasons.