While hovering over Yoshi or any of his outfit variations on the character select screen in any mode, there is a chance that he will hum Totaka's Song, a short melody written by veteran Nintendo composer and Yoshi voice actor Kazumi Totaka that has been inserted into most of the games he worked on. Although Totaka was not part of the music team for Mario Kart World, he is credited for reprising his role as Yoshi.

Although the DK Spaceport course is primarily based on the original arcade version of Donkey Kong, there are also a few elements of the course taken from the Game & Watch version of the game. Specifically, the starting banner is modelled after the Donkey Kong Game & Watch unit, and iconography based on the directional pad can be seen throughout the course.

The idea of Mario Kart characters eating various foods and transforming into different costumes originally started as two different ideas. According to Mario Kart 7 and Mario Kart 8 director Kosuke Yabuki, the team almost considered having players buy costumes for specific characters using in-game coins (similar to the way players buy alternate-costumed characters in Mario Kart Tour), with players having to drive to a clothing store rather than the "Yoshi's" fast-food restaurant.

Additionally, the idea of characters eating food was already considered at the very beginning of development, but was nearly removed. According to general game designer Shintaro Jikumaru:

Development on Mario Kart World started as far back as when Mario Kart 8 Deluxe was just wrapping up production, and official work started at the end of 2017 as a title for the original Nintendo Switch. From the very beginning, the game started off as an open-world experience, which is why the game is called Mario Kart World instead of Mario Kart 9. Because of this, having 24 racers in a single game rather than 12, like in 8 Deluxe, was already in consideration.

Technical limitations of the original Nintendo Switch console made development very difficult, and the team shifted to the then-upcoming Nintendo Switch 2 in 2020. In the meantime, the team released the Mario Kart 8 Deluxe Booster Course Pass to fill the void while Nintendo was still working on Mario Kart World.

Because of this delay, Mario Kart World has the longest gap of any mainline Mario Kart game that exists thus far, spanning almost six years from Mario Kart Tour (not counting Mario Kart Live: Home Circuit, or 8 Deluxe). The longest ever gap prior to this was the gap between Mario Kart 64 and Mario Kart: Super Circuit, which spanned almost five years.

According to an Ask the Developer interview, the idea behind "NPC drivers" (playable characters that also appear in the game as background elements such as obstacles) came about after a designer drew a sketch of a cow from the Moo Moo Meadows course driving a car. This led art director Masaaki Ishikawa to realize the potential for using the course surroundings as playable characters, feeling they wouldn't look out of place in the game, and Cow was added as a racer alongside other characters like Cheep Cheep and Pokey. This also inspired the idea behind the Kamek item, which turns the racers into playable NPCs, and other obstacle characters built off the design of Cow such as Camel and Giraffe. Ishikawa would later joke that "Cow is actually a pivotal character in the Mario Kart series."

In the lead-up to the release of Mario Kart World, the official Mario Kart Facebook account made a post promoting it with the quote:


This is a reference to a stunt pulled in 2004 on the talk show "The Oprah Winfrey Show", in which Winfrey gave away new Pontiac G6 cars to her entire studio audience while repeatedly yelling "You get a car! You get a car! [...] Everybody gets a car!"

A year after the release of Mario Kart 8, a hip-hop dance known as the "dab" would gain prominence in mainstream culture, becoming a popular internet meme. Mario fans later noticed that at certain angles, one of Donkey Kong's Jump Boost animations in Mario Kart 8 coincidentally resembled a dab, with Donkey Kong holding his head down and stretching out one of his arms, but keeping his other hand close to his head. In Mario Kart World, this animation returns in a different context. While Donkey Kong now faces his head forwards while doing the animation, straying away from dabbing, he also stretches out both arms, making the similarity to dabbing more prominent overall.

According to Donkey Kong Country animator and character designer Kevin Bayliss in 2019, when Rare co-founder Tim Stamper and Nintendo tasked him to redesign Donkey Kong and "bring it up to date", he originally wanted DK's design to be "compact" similar to how NES characters were previously designed, and wanted the character to show up "nice and clearly." When designing DK's new facial features, he used the same design as the Battletoads' eyes, noting that gorillas "look like they got this big brow". He later expressed frustration in 2025 that this design choice always made DK look "annoyed", in defense of a new, contentious redesign of the character first introduced in the 2023 film The Super Mario Bros. Movie and later incorporated into Nintendo's games starting with Mario Kart World.

Many players assumed that the redesign was derived from his appearance in the film, resulting in complaints that it represented a sterilization of the character's public image. Closer to the release of Donkey Kong Bananza, the game's producer Kenta Motokura and the character's creator Shigeru Miyamoto explained their reasoning for the redesign. Motokura revealed that the design was first conceived for Donkey Kong Bananza before being applied to Mario Kart World and the film, and was made to account for the former game's 3D gameplay. He stated that they first accounted for how players would spend the majority of their time viewing DK from behind before snowballing into more substantial "creative adjustments," using his design from the original arcade game as a reference point; Motokura quipped that they "returned to where it had all started" while overhauling his design. According to Miyamoto, the redesign was intended to make DK more expressive, citing Donkey Kong Jungle Beat as the starting point to the new direction they took his design.