Actor Allusion: As the hotel concierge (played by Tim Curry) flees from the hotel room in the second movie when he is threatened by a recording of Kevin's uncle, the recording says "Oh, you're cooking, Frankie!", which is an allusion to Curry's previous role as Dr. Frank N. Furter from The Rocky Horror Picture Show.
Defictionalization: The Talkboy from Lost in New York was originally conceived as a non-working prop for the film; one letter-writing campaign from 1990s kids later, and it was Defictionalized by Tiger Electronics. It sold well enough that several variants were created, such as a pink-and-purple version called the Talkgirl.
Doing It for the Art: Daniel Stern was so committed to the role of Marv, and to the concept of Marv and Harry being the Wet Bandits, that in fact, a number of Marv's antics (sticking snowglobes to the dashboard with gum, stepping on and walking across glass ornaments, trying to pry open the back door with a crowbar before giving up and just opening it, the stupid look on his face before getting hit with a flying paint can, the "Why the hell are you dressed like a chicken?" line he says when he sees Harry covered in feathers) were ad-libbed by Stern.
Kevin's younger cousin Fuller is Macaulay Culkin's little brother Kieran.
The elf that Kevin meets before talking to Fake Santa in the first movie, and the New York airport desk clerk in the second movie was the then-wife of cinematography Julio Macat.
A few of director Chris Columbus's relatives also appear in the first two movies as extras.
Similarly Named Works: "Home Alone" is also the name of an unrelated public service video that shows viewers what to do if they're at home by themselves (i.e., if someone calls on the phone, don't say you're home alone, etc).
The first two movies would last 15-20 minutes if filmed today; cell phones. Both the DVD commentary and CollegeHumor pointed this out. Instead, the setup would have to involve Cell Phones Are Useless.
Part of their central premise is that Kevin *enjoys* being alone and in the first, he feels as if the house is "his house" and he must defend it. The cell phone idea assumes that Kevin even has access to a cell phone; many parents do not let children under the age of 12 have one.
Sadly, this is not the case anymore.
Out of all the valuables in the McCallister house coveted by the Wet Bandits, Harry mentions that the house likely contains multiple VCRs.
Catherine O'Hara forgot her lines in the airplane scene where she realized that they left Kevin Home Alone. In fact, the iconic shouting of Kevin's name? Her attempt to salvage the take.
The conversation with the checkout lady and Kevin in the first was improvised. The director didn't say 'Cut', so the actress kept asking him questions and Culkin went along with it.
Gus Polinsky's story about he and his wife leaving their kid at a funeral parlor all day long was completely ad-libbed by John Candy; matter of fact, many of the moments between he and Catherine O'Hara saw a lot of ad-libbing, as both are SCTV alumni.
The car belonging to the Santa actor actually does stall on camera as he attempts to drive it away.
Unintentional Period Piece: As any keen viewer will point out today, the plots of the first two Home Alone films are so strongly reliant on the analog, pre-9/11 world of the early 1990s that they would be largely improbable in the 21st century.
If this film were made in 2012, Kevin's parents could have just called him on a cell phone as soon as they discovered he was missing; (His parents discovered he was missing during the flight to Paris. They had to wait until they landed, but were still unable to call the house due to the phone lines being down).
Harry and Marv probably would have never discovered that Kevin was alone at the house (Kevin had fooled them repeatedly into thinking that the house was heavily occupied. It was only after Marv overheard a message from Peter McCallister being recorded onto an answering machine of the Murphy house while they were burglarizing it that they began to figure out that Kevin was alone in the house and was screwing with them. Answering machines are all but gone today, in favor of private, electronic voicemail, not forgetting that many homes no longer have landline phones anyway.
On top of that, the lax airport security of the time is on full display as well. Kate is able to barter a plane ticket off of a fellow traveler right in the terminal; anybody who attempted something like that today would probably be detained on suspicion of being a terrorist.
Or, there's the fact that the McCallisters would have never been able to get through post-9/11 airport security in time to make their flight in the first place, giving them ample time to discover that Kevin is missing and go back home to get him, preventing the plot of the film from ever unfolding.
We have Frank tell Peter, "There's no way on Earth we're gonna make this plane. It leaves in 45 minutes" before they get in the vans at their house, located in Winnetka. A Google Maps analysis shows that without traffic it is a half-hour drive from 671 Lincoln Avenue to O'Hare International Airport. Given Chicago's expressways are known to be very congested in both directions at rush hour due to the city's reverse-commute nature, the travel time would actually be closer to an hour. The McCallisters would have missed their flight by more than a good hour because of the traffic one would face trying to catch a morning flight, and then adding the time it would take for them to check in, print boarding passes, wait in the security line, clear the security checkpoint, and then make their way through Terminal 3 to their gatenote American Airlines is based out of Terminal 3, along with Delta Airlines. There's a reason why the airlines generally recommend that you arrive at the airport a full 90 minutes before your flight.
Mocked by Honest Trailers, who encourage you to "bundle up and relive the early 1990s joy of Micro Machines, starting lineup figures, Johnny Carson, 35 mm cameras, landline phones, answering machines, pre-9/11 air travel, and Macaulay Culkin."
If Home Alone were made today, that could still make for an interesting plot: The McCallisters wake up late due to a power outage, run off to the airport in attempt to still make their flight which they miss due to not being able to get through security and into the terminal in time, discover that Kevin is missing, then go running around the airport and suburban Chicago trying to find him. Fearing the worst, the eventually discover that they simply left him behind at the house by mistake.
For a simple answer, this trope is pretty much played straight: director Chris Columbus has said that he and John Hughes wanted very much for Home Alone to have a "timeless" look and feel to it so that ten, fifteen, twenty, etc. years down the line, it could still be viewed and enjoyed by people and it not seem "dated". Unfortunately, this wasn't the case.
Home Alone 2: Lost in New York
No way in today's world would anyone even consider just letting a kid under age 10 with no boarding pass or parent/guardian around board a fully-booked flight to New York.
Even by 1992 standards, that is still a pretty boneheaded move on the airline's part. True, the attendant that let him on the plane did ask him if he saw his father and Kevin said yes after seeing a man from the back who was wearing the same style of coat as his dad was wearing. However, even before the hijackings of 2001, the flight attendant would have walked up to the man and said "Excuse me sir, are you this boy's father?"
An even more boneheaded move was letting the McCallisters flight take off with Kevin's unaccompanied baggage, post-Lockerbie (though we don't know if Kevin's baggage was checked to Miami as part of someone else's checked bags).
According to director Chris Columbus, and early promotion posters, the original Home Alone music score was to be composed by Bruce Broughton, who ultimately got caught up with scoring The Rescuers Down Under, and was unavailable to score Home Alone.
Also, according to Columbus, John Hughes wanted to film Home Alone 2 and Home Alone 3 back-to-back, but 20th Century Fox declined to do so.
Hughes' original concept for Home Alone 3 was to be about Harry and Marv doing a Heel-Face Turn, moving to the suburbs, next door to each other, raising their own families, while Kevin does a Face-Heel Turn, and is released from jail, when he decided to exact revenge on Harry and Marv.
Sigourney Weaver was considered for the role of Kevin's forgetful mom, but didn't get it. Probably would have clashed with her protectiveness in Aliens anyway.
And if Home Alone 4 was successful? We would've had a TV series about it on ABC Family. Within the film, Kevin's parents didn't get back together in an earlier script. The ending was rewritten in case they ended up making the show.
In the commentary for the first film, Chris Columbus said that he had planned for Home Alone 3 to be filmed right after Home Alone 2, which would've starred Macaulay Culkin again (Though it is unknown if there would be any difference between the original idea of Home Alone 3 and the one starring Alex D. Linz).
According to AMC's Story Notes, Joe Pesci once said that his idea for a 3rd film would be Kevin lost in Hawaii, or a beach resort.
In the original script, Uncle Frank was the real mastermind behind Harry and Marv robbing the McAllister house.
Daniel Stern refused to reprise his role as Marv in the fourth film, saying it was "An insult, total garbage." Day-um. Keep in mind he has A Christmas Story 2 on his resume.