In the opening sequence of the game, a Bait-and-Switch recreation of the DeLorean demonstration from the original film, the player can freely choose multiple dialogue options, but an achievement ("Deja Marty") is unlocked if the player sticks to Marty's lines from the film.
Marty sees a sign for a production featuring a real shark, echoing his experience with Jaws19 in Back to the Future Part II.
The Sisters of Mercy Soup Kitchen is located where the cafe and saloon were in the films. And it wouldn't be complete without a "HEY, McFLY!!"-scene with similar lines.
Artie's first scene has him (unknowingly) mimicking Marty rubbing the back of his head, similar with Marty and his father's younger self in the first movie.
Marty's mother waking him up at the start of Episode 1, which makes it a Good Morning, Crono, albeit it's the prime version of her this time rather than her as a teenager, one from a Bad Present or coincidentally George's great-grandmother.
Marty's experience with the amplifier, except that in this example, he uses it against Biff. Meanwhile, Biff using the amplifier mirrors Marty's actions from the first film. Marty even mentions that it took him forever to fix it after the last time he blew it out.
Marty arrives at 1986 Edna's apartment being towed on his skateboard by a pickup truck, like he does in the first film.
The first scene in the Soup Kitchen is the per-requisite bar scene, complete with "Hey McFly!", a Tannen scolding a relative McFly for his incompetence, and even a reference to the original scene by having Kid Tannen look towards Marty and say "What are you looking at, punk?". It's also notable that the McFly relative, as in 1955, is minding his own business and simply eating at the start of the scene. It also has a Tannen making an incorrect statement that is corrected by a person nearby. "I don't think [Babe] Ruth is a pitcher anymore."
Marty clinging onto a vehicle being driven by Tannen mirrors the similar scene in Back to the Future Part II, down to trying to secretly snare an important plot point without his noticing.
If Marty turns on the TV in Doc's garage, he watches a short clip from Carl Sagan's Cosmos: A Personal Voyage in which Carl wonders whether nature would allow a time traveler to prevent his own conception. Cue Marty looking over to his dad and smiling.
Marty's dad mentions that sometimes, you gotta go out on a limb for the ones you love. Apt, given that he met his wife after falling from the tree branch from which he was spying on her.
A bunch of the newspapers in Edna's collection reference past events if you haven't identified when the speakeasy burnt down yet.
Episode 2: Get Tannen!
One area of this game has Marty having to avoid interaction with himself, much like he did in Back to the Future Part II.
In 1986:
When going to the side door, Marty decides to "try the front door, just in case" something like in 1985-A (BTTF Part II) happens.
Marty telling something only he would know to his dad George: what he did when he was eight, or how George met Lorraine.
During the Biff scene, a reference is made to when George punched Biff, and when Biff crashed into a manure truck - apparently a more recent crash than the one in 1955, prompting a confused Marty to ask, "Which one?"
Looking at the gazebo in the daytime in 1931 has Marty mention his band, the Pinheads, from the first film.
Young Emmett mentions requiring 1.21 kilowatts for an experiment. Later, when preparing to use his prototype flying car, he says a line similar to one that Doc says in the first film (and in Episode 1).
Emmett says that his flying car could make accidents and traffic jams a thing of the past. He's completely wrong; as seen in the second movie, the airways could suffer from accidents as almost caused by the DeLorean spontaneously appearing in traffic, and one look at a billboard told Doc it would take them "forever" to reach Hilldale because the skyway was jammed.
In the new speakeasy:
Marty tries to sing "Johnny B. Goode" on the microphone.
Marty almost orders a Pepsi at the bar, though Pepsi Cola did exist at the time, since it was created in 1893.
Episode 3: Citizen Brown
Marty lampshades that he's destroyed the car again, and really shouldn't be allowed to drive it anymore. Note also that when Marty asks alt-1986 Jennifer for a lift into town, she drives past him — just like the elderly couple in the first film.
When Marty finds his dad George, he says, "He's a peeping tom!" There is also a box of peanut brittle (referencing a deleted scene from the first film).
Marty mentions the time he set fire to the living room to his mom Lorraine.
Marty can say: "Rock n'roll is my density— er, destiny!" This is just one of several possible random lines of dialog from that scene, the best being, "He might be good with the guitar but I invented Rock and Roll!"
Biff messes up a turn of phrase and gets corrected by someone else (who calls him an idiot in the process).
Biff stands up tall against Marty as in the films.
When talking to Citizen Brown about the DeLorean time machine, Marty says "You built a time machine... out of a DeLorean!" identically to the way he said it in Back to the Future (and subsequently Episode 1's opening), emphasis and all. Not to mention that Marty tries to restate what Doc meant to tell him about the DeLorean's steel frame being perfect for time travel, also from Back to the Future... except he doesn't know exactly what that is.
Citizen Brown derisively calls Marty "Time Travel Boy" before kicking him out of his office. He is imitating 1955 Doc, who mocked Marty by calling him "Future Boy".
Episode 4: Double Visions
Jennifer notes Marty is wearing Calvin Klein underwear.
Jennifer: "Really?"
George decks a security guard harassing Lorraine, as Marty commends, "Alright, Dad!"
When Marty picks up a can of used oil from the rocket car in Emmett's lab:
Marty: "Gross!"
Emmett: "Accounting doesn't enter into it!"
After Citizen Brown took six months to fix the time machine and went back to get Marty, he mentions that the time machine repairs involved his family fortune and "a sketchy deal with some Libyan nationalists", the same things used to build the time machine originally.
Marty, his guitar, and giant amps once again play a part in the story. Not to mention that the final puzzle of the episode involves Emmett, the clocktower, and an oncoming lightning storm.
The Mind Map card on top of the stack is one taken from Red Thomas, Hill Valley's mayor-turned-bum. There's also a poster asking people to re-elect him at the Science Fair.
Emmett's photo album is titled "Von Braun Family", which Doc said was his family's name when they came to the U.S. before changing it to "Brown" during WWI.
One of Emmett's boxes for the expo is a Peabody apples box. Peabody was the farmer in the first film who was obsessed with pine trees.
Marty, at the "Hill Valley of the Past" diorama, looks at a T-Rex model and mutters, "If this thing is called a Tannenosaurus..." The animated series did feature a dinosaur Biff.
Episode 5: OUTATIME
For starters, the title: The other four titles have been straightforward in their explanations, but the finale is simply called 'OUTATIME'. It makes sense when you remember that's what's spelt out in the DeLorean's original Vanity License Plate. In addition, it's the last thing seen of the DeLorean when it's destroyed in III (albeit in bar code), indicating it’s finality.
Marty wakes up in his trademark sleeping pose from the movies. Once again, it's Emmett Brown's phone call which jolts him awake.
One of the exhibits at the science fair is "Enlightenment Under the Sea", a reference to the "Enchantment Under the Sea" event which will take place in 1955.
Great-grandpa Willy makes an appearance - voiced by Michael J. Fox!
Marty: Hey! That was my great-grandpa Willy! He peed on me!note In 1885, Marty holds an infant Willy McFly and then realises that he peed on him.
"He stole his wallet! I think he stole his wallet!"
Artie says you have to go out on a limb for the ones you love. His son took that to heart.
Crazy hermit Edna's primitive alarm system includes a couple of Frisbee pie tins. Marty of course uses one of these as a frisbee to disarm Buford Tannen in 1885.
The final playable sequence involves Marty clinging to a vehicle from the outside once again. It's not driven by a Tannen this time, but the hoverboard makes a triumphant return!
A final conflict without a Tannen? MADNESS. Actually not, Edna Strickland, the driver, is destined to become one in the final timeline shown when we go back to 1986, and a happy one too for the bonus.
Speaking of Tannens, Beauregard Tannen is actually a Tannen from the animated series!
Doc mentioned Verne having a 21st century video game console cache, which included an Xbox 360 according to the headsets he and Marty use at this time. This alludes to how, in The Animated Series, Verne was a huge video game addict.
The ending of Episode 5 and the entire game as a whole pays homage to the ending of the first film, right down to someone asking if their future selves become "assholes", but no, it's about their future descendants needing help...and then it goes way off the rails Parodying the scene with three Martys coming from three futures with a DeLorean each.
Throughout the series:
Once per Episode, Marty using the classic "What the hell is that?!" and pointing behind who he's talking to. In Episode 5, Edna pulls it off. Marty actually falls for it. Officer Parker lampshades, "One of these days, I really should stop falling for that!"
Kid Tannen winds up going into a pile of manure, of course. No "I hate manure" line, though.
