A movie that has been analyzed to death.
I love this movie though. I like it better than Part 1. Granted, without Part 1 the motifs and callbacks wouldn't make much sense. This is a very well written script however you slice it and one I'd love to write as good in my own career.
So let's really criticize and talk about Part 2.
First, I want to bring up the scene where Biff is in a hot tub watching an old western movie of Clint Eastwood's where Marty confronts him about the Almanac. This foreshadows Part 3. Eastwood is seen being gunned down by someone. He stands up to reveal a "bullet proof vest" according to Biff. A metal armor, under his clothes. Part 3 would bring this to light.
Before he goes into Biff's Hotel and Casino his lineage is mentioned as being Gifford "Mad Dog" Tannen. This is where Marty elects to do it the "easy way" as he knocked out by Biff's goons.
There is the talk between Loraine and Marty's daughter about the race with the Rolls Royce in this film that we don't see actually happen until the end of Part 3.
Part 2 is the last film that really makes callbacks to the motifs and lots of foreshadowing.
Marty and Biff confrontation: "What the hell is that?"
Old Biff: "There's something really familiar about all of this." during the hoverboard chase calling back to Marty being chased in 1955 by Biff's goons.
The manure truck. End of story.
Waking up after being KO'd by your mother. "Twenty seventh floor?!" "1955?"
The entire Enchantment Under The Sea Dance sequence, and it's long.
Wild Gunman. This is an arcade game Marty plays in 2015. Famous for having a young Elijah Wood. This would be repeated again in Part 3.
When Marty goes into Biff's office confronting him about the Almanac Biff pulls a gun on Marty. Marty, after removing a pack of matches, uses it's holder as a frisbee to throw at Biff's head. The frisbee use returns in Part 3.
Doc mentions in Part 2 that the Old West is his favorite time in history. As well as the "greatest mystery", women.
More than once we're shown the dashboard of the time machine. when it malfunctions it points to January 1, 1885. Curiously, this is not where Doc is sent back to. Not January anyway.
Needles. The groundwork is laid, and we know about him from Part 1, everything is there for us to determine the nature of the incident in Part 3, but it's well written apart and seemingly unrelated, until we see it.
Moving on...
The point of view in 1955, despite following Marty, changes the entire perspective of that day, November 12, to the point of view of Biff. I wonder if they had a graph, chart, or something to track where each character was and when. This, to me, flawed writing, loopholes, plot holes, o not, is great writing. It's hard to remember every detail, especially as it wa filmed against written, when trying to create the same event from another view. Try it. Try and rewrite Hary Potter from Draco's point of view

The challenges add up every page.
Some great quotes:
Marty: It feels like I was here yesterday.
Doc. You were! You were here yesterday!
Greaser: How did he change clothes so fast?
Doc has some real ramblers that are hard for me to recall right now. You know what they are.
Strictlan: The school burned down 6 years ago!
Old Biff: Just bet on the winner and you'll never lose.
Strictlan: You're a slacker!
This quote is foreshadowing, but for a part you've already seen. Again, in 1985, when Marty confronts Biff about the Almanac, he retrieves it out of a safe.
Old Biff: Put it in a safe. You don't have a safe. Get a safe!
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This is one of my favorite franchises.
Discuss.