Wondering why doesn't King Boo have his Jewel Crown in later games? Because Luigi sold it to buy his new mansion (even though the jewel is worth 1 COIN).
Luigi doesn't get to the mansion until Mario's been captured. Player 1 lost a life, and now it's Player 2's turn.
You learn from a diary entry in the study that one of the ghost twins is susceptible to cold. This is because planes weren't protected from the weather when they were first built by Orville and his brother.
E. Gadd seems none too shocked that the person making surprise contact with them in the 3DS remake is his own future self. But that makes sense if you remember this isn't the first time he's been the "past self" in time travel shenanigans.
If you look carefully, you'll see that all of the ghosts on the Second Floor are related—Neville and Lydia are married with three children, and Uncle Grimmly, Aunt Petunia, and Nana are their extended family. The only exception is Sue Pea, although many fan theoriesHand Wave this by claiming she's a cousin.
Her name is Miss Petunia. But Nana's diary entry about pranking her makes it seem like they're family, so her being an aunt is possible.
Why does the first child you find in the Twins' Room accuse you of cheating after you uncover the second? Simple — if you're doing it the "right" way, that first twin just saw you expel an element on the box! Of course that's against the rules!
Which loops back to Fridge Logic considering you could use your element on all the boxes first and then open both their hiding spots or if you decided to rely on luck and checked the boxes at random.
A weird meta example: the game is kicked off by Luigi winning a mansion in a contest he didn't even enter. Or, to put it another way: in true Luigi fashion, he won it by doing absolutely nothing.
Why do King Boo and the rest of the ghosts seem so much more terrifying and Knight of Cerebus in this game when compared to their other appearances? Simple — because in those games, we are seeing the ghosts how the Fearless Mario sees them, but in this game, we see how the Phasmophobic Luigi see them.
Many found it weird how Vincent van Gore, the obvious Expy of Vincent van Gogh, is French when the real van Gogh was Dutch. This person was just as confused as everyone else, and then hit upon this trope:
Charriii5: Why is van Gore French? Vincent van Gogh was Dutch. Yeah, he died in France, but that didn't make him - Ohhhh...
And then there's the heart quotes. Most of these are harmless little tidbits of speech that the ghost is keeping to themself. But then there's Sue Pea. It's a hint at how to beat her, but think. What if that quote was her last words?
To people who played Paper Mario, Luigi's cowardice seems weird. In that game, he was eager and adventurous. However, if you read his diary at one point, you can see he was already scared of ghosts. And the first game with Luigi's fearful personality? Luigi's Mansion, where he has to travel through a haunted mansion. Luigi is traumatized. And nobody seems to be helping him.
Luigi's humming and calling for his brother make up a chilling, creepy "soundtrack".
There's those two ghost twin children who love to play hide and seek, nothing inherently wrong with that right? Well if you happen to find a diary in the study, reading an entry reveals that they both like to hide during the game, sometimes causing the game to go on for a very long time... meaning two kids probably starved themselves to death over a children's game.
So Word of God is that Chauncey was actually born a ghost; the immediate assumption is that Lydia and Neville somehow had another baby after they died, removing the inherent horror in a ghost baby. But then... Being born a ghost could also mean that he's the result of a miscarriage, a stillbirth, or the result of Lydia dying while she was pregnant.
It's believed by some that King Boo's Bowser "mech" isn't a mech at all, but rather Bowser's corpse, with the Koopa King having been killed by Mario in a previous game.
Not made any better when Madame Clairvoya herself is shocked by Bowser actually being relevant at all in King Boo's scheme, since she points out that Bowser had been soundly defeated by Mario, and specifically theorizes that King Boo has revived Bowser. If Bowser was still alive after his defeat, then said choice of words wouldn't make much sense. This is made even more horrifying when this also presents hints that Mario may have killed Bowser at some point in the past. Luigi's Mansion is a dark game indeed.
So, the portrait ghosts. Not only are they technically real, albeit dead, people being trapped in paintings against their will (and not all of them are even trying to hurt you,) but: Have you ever gone to the gallery and noticed how they don't move inside the paintings like how Mario does in his painting? They just stand still, forever.
All the area 1 portrait ghosts plus Henry and Orville are members of the same family. That means something horrible must have happened to kill all five at the same time. It gets worse if you notice there is also an Uncle Grimley, Aunt Petunia and Nana who could also be related to this family.
Nana has the key to Henry and Orville's room, implying she is their grandmother, but Petunia is never referred to as "Aunt" in the game.
Sue Pea's death. While most argue that passing away in your sleep is the most peaceful way to go, imagine putting your young child down for a routine nap during the day, only to come back to wake them up a short time later and realize they're not breathing...
There is something quite horrifying about the concept of being trapped in a giant ice cube, all alone in the basement, far away from the rest of the residents. Thankfully, this is being described as Sir Weston’s wish in his description and gameplay shows he’s able to move inside of his ice prison.
Checking the Secret Altar during the blackout reveals King Boo has disappeared. Check again once the lights come back on, and he's back staring at Mario's painting like nothing had happened. This is never explained. So where exactly does he go, and why?
King Boo himself will never appear or do anything to you during the blackout. Almost as if he's just... watching you the entire time, taking joy in seeing Luigi terrified by the endless number of ghosts that appear to attack him.
Worse, imagine it from Mario's perspective: the lights in the mansion suddenly shut off, and your captor suddenly disappears, leaving you all alone in complete darkness. Then, once the lights come back on, they reappear without an explanation acting like nothing happened. Keep in mind, Mario knows his brother is in the mansion, so for all he knows, King Boo must have done something to him while the lights were off, and he has no way of knowing what happened, or if Luigi is even ok. No wonder why Mario is so relieved when he sees Luigi walk into the Secret Altar.
was just as confused as everyone else, and then hit upon this trope:Charriii5: Why is van Gore French? Vincent van Gogh was Dutch. Yeah, he died in France, but that didn't make him - Ohhhh...