Six months after the American release of Super Paper Mario, American film director, producer, and screenwriter Seth Gordon, who's most recent works include the Pixels movie, had interest adapting a movie based on Super Paper Mario. Gordon was quoted saying, "I'd love, really love, to adapt Super Paper Mario into a movie, a movie that would constantly switch from 2D to 3D. In five years, 3D cinema is going to be really big." Gordon however specified that he never had the chance to speak with Nintendo about his envisioned project, so his idea was eventually forgotten.
The Underchomp is based on the legendary hell-hound Cerberus, a giant three-headed dog who guarded the gates of Hades in Greek mythology. In one story, he was put to sleep by the music of Orpheus, which inspired Piccolo's music putting the Underchomp to sleep.
A Gold Fuzzy makes an appearance on the back cover of the game's official guidebook, but no Gold Fuzzies appear in-game.
An early title screen can be found in the game's files. This is almost identical to the final, with two differences: The copyright year is 2006 instead of 2007, and Thoreau's spot is occupied by a strange ladder-type Pixl that also appears in early screenshots.
In the game's coding, there are a total of 9 unused enemies, some of which were present in the first Paper Mario game.
In the German version of the game, Francis the chameleon is named Konrad, a pun on Conrad, which is a popular German PC store.
There are six unused audio tracks in Super Paper Mario. The first one is named "Dummy_32k". Dummy plays the tune of World 1-1 from "Super Mario Bros 3." Another is named "b_happy_flower_44k_lp." It's name suggests it was going to be used for when Mario uses the Happy Flower item. The next audio track is called "evt_relax1_44k_lp." This track is a peaceful, relaxing tune. It might been planned for use near the end of the game. The 4th audio track is called "evt_stg3_open1_44k_lp." It was most likely going to be used for a opening of a level in World 3. The next is called "ff_corrrect2_e3_32k." This unused jingle's name suggests there was supposed to be more than one jingle. The final unused audio track is a jingle named "ff_fault1_32k." This was most likely going to be used when failing a Mini-game.
Super Paper Mario was originally going to be released exclusively for the Nintendo GameCube before being moved to the Wii. Evidence exists on the game's data, as there is a folder which contains GameCube rendered models of characters like Mario and Princess Peach. The Wii textures are about 50% larger.
There's an unused enemy in the game's data named "Fly Guy" which is a Flying Shy Guy using a propeller. It's unknown where this would have been used in the game.
In both of Francis' rooms where he keeps his keys, there are references to previous Paper Mario games. Bow the Boo and her butler, Bootler, are found on a poster along with Petuni, who also appears as a plushy with Punio, Vivian, the Yoshi Kid in all colors, Peach, various items, and Pennington. The left most room also contans a famicom/NES, a SNES, a Virtual Boy, a Nintendo 64, and a Gamecube.
Near the end of the game, Dimentio will ask you to join his side to take down Count Bleck. If you say yes four times, he will enslave the characters and you will get a game over.
The enemy Fracktail makes a reference to Zelda II: The Adventure of Link. When Dimentio causes Fracktail to short circuit, he says "I am Error", one of the NPCs in Mido Town.
It is possible to get a game over at the beginning of chapter 4-1. After getting the helmet go into the door. When it asks you if you want to put on the helmet, say no. Do this until Tippi says "If you don't, do you have any idea what your fate will be? AWFUL. Do you want this?" Answer yes to every question after this. After this Tippi will leave and you will get a Game Over.
Near the beginning of the game, Merlin tells you to take the pure heart and save all worlds from destruction. If you say no three times, you'll get a game over.
The data in Super Paper Mario contains an unused title screen. In Thoreau's place is a Pixl who resembles a ladder which was not included in the final game. The Pixl also appears in a pre-release screenshot of the battle against Big Blooper.