Changes in BttF2:
- Remove opening scene which repeats the last scene from BttF1 with Elizabeth Shue. In the world of acting, one role can be played by different actors. No repeat needed. Or, you could replace this scene into the end of BttF1 and it becomes one of the changes from Marty tweaking history in the first movie (cuts 2m20s).
- Remove Doc's "old" make-up reveal. The joke didn't work for me because the difference wasn't noticeable enough.
- Shortened Marty's walk in the 2015 town square to remove product placements (kept the Jaws 19 holo-shark!).
- Shortened Marty's entry into Cafe 80s to remove Ayatollah vs Reagan reference which didn't age well.
- Trimmed young Griff's lame jokes in Cafe 80s, they didn't add to the story (who will really miss "your shoe's unfelt"?).
- Slight trims in the Hoverboard chase, for pacing.
- Removed old Biff's surprise at seeing a flying Delorean again after 30 years (because that scene is cut). Now he's surprised at seeing 2 Marty's.
- Trimmed cops dialog upon arrival in Hilldale, now they bring Jennifer home without dissing the neighborhood.
- Cut Marty Jr watching many TV channels and Marty Sr walking in on that.
- Slight trims to old Lorraine's exposition and the family's dinner conversation.
- Cut Marty Jr complaining about the metal fruit basket. We saw it in an earlier scene, so we don't need to see it come down to understand that it's there.
- [Non-change] I had inserted the Deleted Scene of old Biff fading out of existence after returning in 2015, because it answers the question of why Biff is hurt / exhausted climbing out of the DeLorean. I took it out again upon realizing that it raised more questions than it answered.
- Small trims in Doc's dialog as they fly back to 1985, for pacing.
- Small trims in Marty's escape from "his" bedroom. Again, for pacing.
- [Major change] When Marty realizes things are wrong, would he really wander into town? No! He runs to Doc's house as fast as he can! Doc is the only person who may be able to fix this, the only person who'll believe him. And Marty has to reach Doc before he destroys the time machine since they'll probably need it to escape this wrong 1985. After many transition try-outs, settled on a hard cut from Marty running to Doc's lab. A) No more Mr Strickland on his porch, now Doc confirms it's 1985. B) No more 80s bikers. C) No more confused stumbling into town, Marty now visits Biff Tower after Doc explains what's happened. D) No more graveyard, so Doc no longer has to wait there for Marty. E) Marty learns George is dead from the newspaper (cuts 3m19s).
- Marty visits Biff Tower only once. He no longer has to get back in after Biff ordered him out. The original first visit is largely retained, now placed as the start of his visit.
- Slight trims to Biff's dialog inside Biff Tower, for pacing. Same for Lorraine.
- When Biff storms out of the room and orders Marty to leave (the end of the original first visit to Biff Tower), we go straight to Biff in the bath (the start of Marty's original second visit). Now, after Marty's initial confusion ("Mom?") and anger (at Biff) he regains his composure and remembers why he came here.
- Small trims to Biff chasing Marty.
- Trim Biff's dialog, removing his claim to murdering George. It's easy script-writing to have all events caused by the main characters, but it doesn't make the story any better. Biff is gross enough for the viewer to cheer against him, without claiming he murdered Marty's dad. This makes George's death less significant in the plot, a symptom of the bad 1985 instead of targeted evil from Biff.
- Small trim in Doc's dialog as they travel back to 1955.
- Small trims to Marty watching Biff's house, following Biff, Biff talking to Lorraine. For pacing.
- Remove Doc meeting himself (from Part 1). Fun in concept, didn't work in execution (cuts 2m28s).
- [Major change] Remove "Oh, La, La" magazine, reducing the misdirection. It does mean we lose most of Mr Strickland. Replace scene of Marty (from Part 1) driving up to the dance with a shorter BttF1 scene of Marty driving up (for continuity). Marty (Part 2) still slips past the car with Marty (Part 1), then bumps into Biff's goons as he turns the corner (cuts 4m18s).
- [Major cut] Marty doesn't run back into the dance, instead he hides from the goons in a classroom. Inserted a wipe to signify passage of time. Now Marty no longer causes the bullies to chase his Part 1 self, and doesn't sandbag them to rectify that. Reliving the song from Part 1 was a fun moment, but it lasted too long. Plus, you watched Part 1 in the past days or even hours, not three years ago. So the song's repeat doesn't have that emotional pay-off anymore (cuts 4m00s).
- Trim Doc's dialog with Marty that referred to cut bits.
- Biff now catches up to Marty when he gets distracted looking at his parents.
- Slight trims to the chase in Biff's car. For pacing.
- Slight trims to the Western Union man's dialog, to remove the misdirection of him starting out creepy.
- Remove the trailer for BttF3. Redundant, because you're going to watch that right after BttF2! (cuts 55s).
- Smoothed out audio transitions throughout. So... Many... Transitions.
- Sped up closing credits by 13 seconds to fit closing FE logo inside BttF2 closing soundtrack.
- Added FE logos at start and end.
- Updated the English subtitles (not hard-coded).
- Added the Director's Commentary. It's shorter than the film and not a scene-by-scene, so no editing required.