Milestone Celebration: "Doc Brown Saves the World" was released on the franchise's thirtieth anniversary to explain why 2015 is nothing like what was shown in Part II. Long story short: Doc retarded human development to prevent Griff Tannen from causing a nuclear holocaust out of petty spite.
Trope Namer: These movies named the following tropes:
The original time machine was a modified refrigerator, changed because it would have been a very stationary prop and Steven Spielberg had images of children locking themselves in the fridge to the horror of their parents. (That's right, Steven Spielberg didn't want characters climbing into refrigerators.) They also would have driven into the blast of a nuclear bomb to fuel the flux capacitor, changed because that alone would have doubled the production costs and the clock tower lightning strike made a fairly simple and stationary location. In the script written for this kind of time machine, the original timeline's Biff became a cop that kept "borrowing" stuff from George and had a daughter. With the change in the timeline, Biff became a security guard working for George, who became a boxing champion in that script.
Eric Stoltz was originally cast as Marty; apparently only stills exist of his work on the movie except for one scene that made it into the final cut — Stoltz running away from the terrorist van, entirely covered in a radiation suit. Footage of this has recently been released.
When initially casting Marty, the producers narrowed it down to two choices: Stoltz and C. Thomas Howell. Zemeckis and Gale preferred Howell, but the executives preferred Stoltz, so Stoltz was cast. However, the execs told the Bobs that if Stoltz didn't work out, then they could go back and reshoot with another actor. Except no one expected it to actually happen...
Other actors considered for Marty included Ralph Macchio, Robert Downey Jr and Charlie Sheen.
One of the little kids in the Cafe 80s (who mocks Wild Gunman for being a game that you have to use your hands to play) is played by a very young Elijah Wood, in his first film role.
Needles, Marty's boss in 2015 and road-racing opponent in the final version of 1985, is Michael "Flea" Balzary, bassist for the relatively unknown world famous funk-rock band Red Hot Chili Peppers.
Charles Fleischer, who provided the voice of Roger Rabbit, plays Terry, the mechanic who fixes Biff's car in 1955 and becomes the old man who asks Marty to save the clock tower in 2015. Might double as a Shout-Out to Who Framed Roger Rabbit?, another Amblin film.
From the same movie, in the 2015, int the 80's shop where Marty buys the Almanac you can see a Roger Rabbit doll. Both movies were directed by Zemeckis and they both have Chris Lloyd starring in there and scored by Alan Silverstri.
Shrug of God: Don't ask Bob Gale what "lithium mode" means.
According to Bob Gale, ideas proposed for Part II included a visit to Doc's family (with Christopher Lloyd playing his mother), and going to the days of Prohibition when Biff's ancestor was a bootlegger.
The last bit was retaken for the first episode of the video game. And yes, Bob Gale worked on it.
The sequel originally had Doc and Marty going back to the 60's after Biff's interference and seeing Marty's parents as pseudo-hippies, and part of his goal would have been to ensure that he is conceived. About mid-way through writing this part, they realized that there was nothing really stopping them from revisiting the events of the first movie. In that version, George was already dead in 2015 (and it was NOT 2015-A). It was mentioned that, at some undisclosed moment, George's life had been saved at a hospital that had previously survived an attempt from the town to demolish it. In the timeline where Biff became wealthy, the hospital had been demolished.
You can read about this version and its associated tropes here.
The band at the town hoedown was ZZ Top, complete with signature spinning instruments.
Averted, but worth mention: President Ronald Reagan was a big enough fan of the series to reference the Flying Car future of Part II in his speeches, and of course was a veteran actor himself. He purportedly wished he could have played the mayor of the 1885 Hill Valley, and it was even seriously considered at one point. It's to the detriment of film history that it didn't happen.
Hilarious in Hindsight: In the episode "Super Doc", Doc, Jules, Verne and Marty end up in 1952. While there, Marty's claims his name to be Jimmy Olsen. Guess who voices Jimmy in Superman: The Animated Series?
The Other Darrin: In a bizarre version of this trope, Christopher Lloyd played Doc in the live action bits, and Dan Castellaneta played his animated counterpart.
Don't forget Generic Guy, Hostile Guy, and (I think) Cue Ball. So Winslow was three times at the speakeasy... simultaneously... That's time travel for you!
Jennifer is voiced by her original actress, Claudia Wells.
Michael J. Fox comes back finally for a special guest role in Episode 5. First as a McFly ancestor in 1931...then as three different future version of Marty before the credits.
The story of the game is based on the unfinished fourth movie script; and expanded on a fair bit. According to Tell Tale games they revived the script, expanded it, and apparently had enough to actually fill up a fifth movie by Episode 4 & 5!
Biff's daughter Tiff was originally going to appear in Episode 3, but with Punk Jennifer there it was decided she was redundant.
There were plans to give Doc and Edna a kid, but they decided against it, due to the ethical ramifications of erasing a person from the timestream.
Ascended Fanon: The series confirms Cracked.com's theory that Doc Brown burnt down his house for the insurance money (though there was a bit more to it than that).
Meaningful Release Date: Issue #1 was published on October 21st 2015, the day that Doc brought Jennifer and Marty to the future in Part II.