Papyrus: IT'S TIME FOR MY BIG NUMBER, SANS! HIT IT! Sans: okay (walks offscreen and hits something) Papyrus: SANS, I MEANT PLAY THE MUSIC. Sans: okay (returns onscreen and plays Losing Horns on his trombone.) Papyrus: SANS!
The song starts with the image of Papyrus with a mic and Sans with sunglasses and holding a boom box over his head, which is hilarious by itself.
As a matter of fact, most of the songs covering Snowdin are pretty funny in general. Given that this is where the human meets Sans, Papyrus and the Snowdin K-9Unit, this doesn’t come as a surprise.
"Undyne", ironically, is half Papyrus being a straight-up riot. He basically starts the sequence singing, with the last verse being...
Papyrus: WHEN I TELL UNDYNE-WAIT, I PROBABLY SHOULDN'T DO THAT, SHE'LL BE MAD, SHE MIGHT HAVE, AND THEN THROW A COW.
Then, when Undyne is singing about how she'll break the human child's little bones...
Papyrus: I CAN'T HELP BUT FEEL THAT THAT WAS A PERSONAL ATTACK...
If you turn on the captions during Let's Dating Fight, all the captions say is the Outback Steakhouse menu. And yes, it does progress throughout the entire video. It then says "Supported by Outback Steakhouse!" followed by "Not actually supported by Outback Steakhouse".
Let's Dating Fight in general is a funny moment incarnate, especially when it reprises Undyne's fight song... for a cooking lesson. Including the backup chorus.
This from the date with Undyne in the final version after she asks you to just tell Alphys hi for her instead of several other more romantic things. Especially funny as Papyrus's reaction gives the implication this isn't the first time Undyne has done this to him:
Papyrus: YOU COULD STILL DO ALL THE REST OF THAT! IT WOULD BE FLATTERING! Undyne: (Running offscreen at him) I'll show you flattery! Papyrus: NO! NOT THE FLATTERY SUPLEX!
Most of Mettaton's scenes, but most point to the part where he puts on a gown and starts singing in falsetto for the opera as the part where they completely lost it.
Just before the opera, we get this exchange:
Alphys: Are you wearing a dress? Mettaton, no... Mettaton:METTATON, YES!
For the Roleplay part of the date with Alphys, instead of Cutting Off the Branches regarding who will roleplay as who, Alphys switches back and forth between playing herself and playing Undyne, all while Frisk just stands there with the same "-_-" expression.
The Shopkeepers' Song. Which is basically the Snowdin Shopkeeper, Gerson and Burgerpants squabbling amongst themselves half the time. Mostly because of Burgerpants, who sounds way older than he should be and a bit like Stan Pines.
"Entry Number Seventeen" is a dark, frantic track, but Gaster shows that beneath it all, Sans got his insistent sense of humor from him.
Gaster: (After No Selling a strike with the Real Knife) I see you didn't MISS me...
Deltarune the (not) Musical
The fact that MOTI decided to add lyrics to "Honksong" at all counts on its own. But then you get the end result of that idea, and it has to be heard to be believed.
During "BIG SHOT", the song itself isn't that funny. However, during the second half, the fight that plays during the song gets its dialogue changed, and fight-Spamton says some fourth wall-breaking and utterly hilarious lines.
Spamton (during the "attack" where he's hit by his own bullets): HELLO? DON'T SHOOT MY FACE AT MY FACE! (is promptly blasted in the face by bullets in the shape of his face)
In "Sans Deltarune", the opening credits are accompanied by the first few bars of "Megalovania" as Sans' eye glows in the dark background. Then the lights turn on and the music stops...
Sans: whoops. sorry. left my hot mixtape on. seems like everyone's got one of those these days.
Also, Sans calls Susie and Kris "little" during the song proper. Susie is less than pleased.
(starting vaguely in the tune of Megalovania) DADADA DA! (gibberish, then camera zooms in and tilts as "WHEN'S MEGALOVANIA" appears on the screen) WHEN'S MEGALOVANIA?! Why hasn't Sans shown up yet?! AAAAHH! (more gibberish, then cut to him examining another thing.)
In the livestream premiere of "But Nobody Came", during the ten minute wait for the Fallen to reappear, some viewers began putting up loads of chocolate emojis, claiming that it would speed things up.