Character mistake: When you reach the final boss in the game, he introduces himself saying "My name is Gee Gus." No it's not. It's "Geegus", no spaces, as shown by the name above the energy bar and the sequels.
Factual error: In the Gamecube version the last entry in George Trevor's diary is dated "November 31st" November only has 30 days.
Suggested correction: While it is true that November only has thirty days, we have to remember that George Trevor has been lost in the mansion without food or water for a long period of time. He also admits that his sanity is slipping away, meaning that he most likely has lost his ability to properly keep track of time. Also, given that he is on death's door, it's very likely that he couldn't think straight.
Character mistake: During the intro, in one line of dialogue Brigitte's name loses the B.
Revealing mistake: There is a safe house in The Following DLC map with two kids playing some hand held video games sitting in a room. If you look at them closely, the screens are not on with the devices not even actually powered on with black screens. Despite this the kids rapidly press buttons like they are playing them, and you can hear the sounds of games being played.
Other mistake: The intro of the game misspells the plural of "hero" twice.
Character mistake: During the first case, after the break, the Judge announces that the "cout" will now reconvene.
Bug: When viewing the starting point's properties, it is possible to lock it to the driving line. If it is locked and physics is turned on, leaving the shack that normally provides the boundaries in the editor is possible. This is likely the reason for why it is not able to be locked to the driving line in the game's sequels.
Character mistake: On the second day when Mr. Higsby is introduced to the class, Mayl states that Higsby is "weird." However, "weird" is misspelled as "wierd".
Other mistake: The suspect James Wong in international localizations of the game (Italian and Spanish that I could personally check) has two discordant dates of birth on the same official FBI file; one is 10/04/1948, the one and only in the English version, the second inside the body of the notes is 11/01/1950.
Other mistake: The title crawl of the original NES game contains several mistakes, notably the antagonist spelled "gannon" with 2 Ns combined with awkward phrasing ("one of the triforce with power" instead of "the triforce of power"). This mistake has been corrected with a better, more fluid translation in later remakes, starting with the Collector's Edition for GameCube.
Character mistake: When you reach the final stage of the tournament, the host Zeus introduces himself and in his rant he says "I'm going to be invincible, immortal and one really tongh muchacho." Whatever "tongh" is. Incidentally, most of Zeus' lines are not really "translated" but rather totally made up - suffice to say, when he suffers his dramatic defeat, Zeus shouts in anger "Why...you...you...YOU CRAZY FUNSTER." Both lines were totally "dry" in Japanese and didn't have funny phrasing and epithets.
Bug: Sky Ruins: right in the beginning you come to a turbine with a large spinning fan inside. On either side is a path, one a dead end the other leading to a switch. There is a door in the wall leading to a third path which is the direction you need to go. You must hit the switch to open the door to get past, unless you exploit this glitch. If when going through the turbine and your Spectraball gets wedged between the fan blade and that door, the collision causes the door to suddenly just begin drifting off and floating through the air slowly and will just keep going. This lets you pass without hitting the switch.
Other mistake: In the character selection screen of the Arcade version, J. Max's profession is "Quaterback", in an obvious misspelling of "quaRterback." The SNES version fixes the typo. Also, to be precise, you shouldn't break the word "profession" into "Profe - ssion" leaving the double S on the same line.
Other mistake: In the multiplayer lobbies when selecting characters, some characters are big enough their limbs or weapons will overlap with the person next to them and clip into their bodies.
Other mistake: The description for the forest snow house reads, "An chillin' house for two Kefkimos." Since the article a precedes an indefinite word beginning with a constant sound with the article an preceding one with a vowel sound, it should read, "A chillin' house for two Kefkimos."
Bug: In Episode II, as Obi-Wan lands on Geonosis, in the shot when the ship comes down, its shadow does not grow as it should.