Might as well start now that some bugs are very noticeable:
Sorted by category and then by order of apearance.
UP-TO-DATE LIST OF ISSUES.
[*]OSX: Some glitches in most scenes, plopping in/out graphics, z-fighting, etc...
[*]When on the steps of the CourtHouse with Artie: Zane's head is too close to his body, like if he had no neck.
[*]Marty's head sticks out of the crate when Cue-Ball's about to get the crate into the speakeasy (clipping).
[*]Cue-ball's forehead sticks out of his hat sometimes (clipping).
[*]When using the lighter on Edna, the camera is placed so that it cuts Edna's face and, in other shot, only her back.
[*]When Marty's talking to himself about not believing Parker will arrest Tannen, Parker takes a drink, but there's no glass in his hand.
[*]Someone experienced Zane's sleeve dissapearing when he should be pointing at something.
[*]Using the lighter on Doc (when Einstein is on the roof) leaves a flame hanging in mid-air.
[*]When Matches goes to tell Kid about the dynamite in the speakeasy (in the case Parker hasn't been set up to arrest Kid), his arm goes through Marty's shoulder.
[*]When Marty uses the shortcut to CourtHouse Square, the barbershop's door has no backside.
[*]When Trixie goes to Officer Parker to tell him about the books and he's not willing to arrest Kid, Parker's glass dissapears and reappears as they argue.
[*]FPS rate drops down in several ocations and, sometimes, the music goes back a second -appliable to Episode 1- even with good hardware. Specially in these scenes:
[*]When Marty sees his younger self travel back in time (music cuts back a second).
[*]When the three Tannen brothers show up for the first time, in 1986.
[*]After Edna asks you if you're headed for the speakeasy (She asks, Marty answers, she talks again, then the game lags).
[*]The rescue Edna puzzle where Kid is shooting out of the window at Marty.
[*]When Marty locks the Harness over Kid.
[*]The ending when Emmett and Edna go to the movies.
[*]When trying to get into the speakeasy to rescue Artie, Marty's "Exterminator" line has a "the" too many in the subtitles ("Your the rats away").
[*]When in 1986 at Marty's home, one of Biff's brother speaks: "No Tannen ain't never been afaid of no McFly!", instead of "afraid".
[*]Inconsistency with Einstein's diminutive: Sometimes is "Einy" and others is "Einie" -appliable to Episode 1-.
[*]Some contractions (like in "Wait til Wednesday" in the speakeasy puzzle) do not have apostrophes.
[*]Zane says "Kid's dame" and is subtitled as "Kid's skirt".
[*]At the gazebo, when you ask Emmett what's he doing, the subtitle says "Hill Vally Expo" instead of "Hill Valley Expo".
[*]When in the flophouse with Doc about Emmett being at the gazebo: "like he's doing...No matter" is missing a space between the dots and "No" and "reanimating the dead,does it?" is missing a space between the comma and "does".
[*]After convincing Parker to do the right thing by using Ednas lyrics, talk to Edna and tell her that Parkers reformed. When Marty speaks, the subtitles say "You'll be happy to know that your Back In Time lyrics have pushed Danny Parker back on the straight and narrow". However the audio that we hear seems to have the Back In Time removed.
[*]Extra spaces between parenthesis in the "nose bleed" talk with Kid.
[*]When Kid is laughing "and then..." has extra "..."
[*]Extra spaces between "rocket car" and "accidentally".
[*]Soundtrack is spelled "Sountrack" in a hint about the music to convince Parker.
[*]Before Marty flies the DeLorean: "Let's find Doc" instead of "Let's go find Doc".
[*]When Marty's flying the DeLorean before going back to 1986: "Is that what you and Edna are doing?" instead of "Is that what's going on with you and Edna?"
[*]In the german version the spoken text sometimes suddenly ends before it should have ended.
[*]Missing time travel sounds when Marty goes back to 4:45 p.m.
[*]No "whack" sound when Cue-ball hits Marty.
[*]Badly timed -and incorrect- time travel sound when Doc and Marty go back to 1986 for the first time.
[*]Audio static from overcompression (heard clearly in Edna's song).
[*]No audio line when talking to Edna about Sagan's innocence -for the second time- (random).
[*]No dialogue from Parker when talking to him about arresting Tannen (random)
[*]No gunshot sound the first time officer Parker fires at Kid.
[*]Several times, when the time circuits are turned on, there's no "ON" sound -appliable to Episode 1-
[*]At the end, when Marty arrives in 1986, the three sonic booms are not in-sync with the flashes.
[*]Some dialogues won't play, randomly, in different runs of the game.
[*]In 1986, Old Kid's about to shoot Marty, we hear him cocking his gun, but when he shows it, the hammer's not pulled back (no animated gun).
[*]On June 13th, Zane moved the window cover sideways to see Marty but, on August 25th, Matches moves it downwards.
[*]Trying to use the control panel for Emmett's rocket car when he's on the roof will make Emmett appear back in front of the control console and, after the sequence finishes, he'll appear back at the roof of the soup kitchen.
[*]Give a caricature to Emmett and suddenly he's back on the floor for the cutscene.
[*]When Marty and Kid are fighting (and right before it when he's holding Emmett hostage), you can clearly see Edna standing at her table like normal, considering you just rescued her and the last time you saw her she was standing with Officer Parker.
[*]OSX: If you're using the keys for the multiple choice selection, then this selection is ignored (probably in favour of the resting mouseposition).
[*]OSX: In rare moments it crashes.
[*]Characters address Marty by multiple names (Sonny, Harry or Michael) -appliable to Episode 1-
[*]When Marty's hiding from his younger self, without taking the stick, clicking on Emmett will turn him to look in Marty's direction only for that shot, without reaction. After Marty's dialogue is over, Emmett is back facing the other way.
[*]If you right-click the first time Trixie sings, the song continues, but Trixie doesn't move.
[*]Subtitles switch on and off when Trixie sings any song.
[*]Marty suddenly stands up when you use the lighter on Parker while hiding behind the car from Kid.
[*]OSX: The game selector still doesn't work properly. Sometimes it hangs whilst trying to connect to the internet, kill task, restart, then it works.
[*]The launcher doesn’t seem to load (stays black) for some people with Windows 7 -appliable to Episode 1-.
[*]If the application is renamed on Mac, the launcher just quits when "Play" is clicked. If the original name without spaces, (BackToTheFuture102) is used, it works fine, but if changed to a prefered name eg “2 - Get Tannen!..." it just quits when play is clicked -appliable to Episode 1-.
[*]Steering controls seem difficult to use -appliable to Episode 1-.
[*]Seems like the lipsync quality went down a notch, except in Trixie's songs, which are spot-on.
[*]When Doc activates the time circuits to input the date to get Artie, the main switch magically goes back to its "off" position.
[*]Concrete skid sounds when the DeLorean skids behind the "Car of the Future" billboard, where there's just soil.
[*]When Zane's outside the Courthouse, he's always seeing everything -our- Marty and Emmett are doing, but doesn't react to the other Marty coming to them (although, this could be explained by being short-sighted, but he still sees Arthur on the second floor of the Courthouse).
[*]Same skidding and time travel sounds for every scene.
[*]Time travel ending sound used twice when Marty and Doc go back to 1986 for the first time.
[*]Air fire trails during as much as the ones on the ground, when those dissapear after a second (as seen at the beginning and end of Part II).
[*]After Einstein appears near "El Kid", if you try to use Artie's pipe on Einstein, Marty says "There's only a few people (and maybe an animal or two) who'd be interested in grandpas smelly old pipe, but this isn't one of them", which is a clue to use it on Einstein in the Find-Artie puzzle. The line now makes no sense since it's already been used -and now, even used on the same element-.
[*]When Marty coughs after helping Edna, only his mouth moves. There are no natural movements or reactions.
[*]The DeLorean's hover conversion struts are in the "ground" position during all the final sequence (the lower part goes through the tire instead of holding it from the center of the rim).
[*]The DeLorean's steering wheel doesn't move -engine limitation?-
I'll be listing more stuff as I remember it and as people post it.