Gradius began development as a sequel to Konami's 1981 shoot 'em up Scramble under the name Scramble 2. According to director Hiroyasu Machiguchi, the decision to make it a horizontal shoot 'em up game was because they wanted to reuse as much of the materials for Scramble as possible during development.

The Namco Gallery versions of Mappy and Family Tennis are outliers among Super Game Boy enhanced games, as they decrease the amount of fine details as opposed to adding them. Mappy removing shading and outlines from sprites, while Family Tennis removes patterns from the court floor. Both of these were likely done to more faithfully capture the multi-color original games compared to the monochrome versions.

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:

The Game Boy version of Mappy released as part of Namco Gallery Vol. 1 had trouble communicating the color-coded trampoline cycle from the original game through the console's monochrome palette. Typically, color-coded elements are replaced with patterns (such as in Dr. Mario and Zoop), but since the Mappy trampolines are too thin to apply a pattern to, they are instead black and become thinner as a workaround. The Super Game Boy version makes them white instead, as it has a black background replicating the original game.

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. Because of the longer-than-anticipated development, the team released the Mario Kart 8 Deluxe Booster Course Pass to fill the void while Nintendo was still working on Mario Kart World.

The plot of DmC: Devil May Cry was written by director Tameem Antoniades, while film director and writer Alex Garland is credited as a story supervisor. Although he worked extensively with Antoniades on the writing and design of Ninja Theory's previous game Enslaved: Odyssey to the West, he had very little known involvement with the development of DmC: Devil May Cry. Antoniades claimed that Garland warned him to be prepared for death threats over the game's drastic changes from the rest of the series, and that "although I'm writing I'm still under his consultation." Conversely, when asked about his involvement in a 2025 GQ interview, Garland only replied with: "Yeah, no, I did fuck all on that."

Mega Man alumn and Mighty No. 9 creator Keiji Inafune (who had joined Level-5 following its acquisition of his company Comcept in 2017) originally served as the producer for Fantasy Life i: The Girl Who Steals Time. However, following "harsh" feedback from internal playtests, Inafune left the company in 2024, forcing Level-5 CEO Akihiro Hino to take over as producer. This led to a major overhaul of the game, as open-world exploration, parkour, cross-play, and cross-save functionalities were added, as well as refinements to the UI, story, and progression systems.

To help promote the game in the United Kingdom and other European countries, Eidos Montréal teamed up with the Irish convenience food company Kepak to hold a sweepstakes advertised on specially-marked boxes of Rustlers burgers and sandwiches until May 31, 2011. The winner and one guest of their choice would have the chance to go on "an action packed trip" to Detroit, Michigan, one of the cities where the game takes place. Rustlers' website promised: "Through a variety of exhilarating activities, you will experience the four skills that are essential to Adam Jensen's survival – combat, stealth, social and technology." It's not known who won the contest, but all entrants needed to identify the country Detroit is located in to qualify for entering. The full list of prizes included:

• Return flights to Detroit
• Five nights' accommodation at the MGM Grand Detroit casino resort hotel
• A three-hour long indoor paintballing session
• A self-defense tactical training session with a private professional tutor
• VIP entrance tickets to the now-defunct V Nightclub within the MGM Grand Detroit and £150 in spending money
• A rooftop dinner at the now-defunct Coach Insignia restaurant worth £100
• An Archos 5 tablet and a Flip HD camcorder

The box art for Fire Emblem: Three Houses features the character Claude upside-down, seemingly as a stylistic choice meant to form a triangle with fellow House leaders Dimitri and Edelgard while crossing their weapons. However, he is mistakenly shifted left-of-center to the point where his bow does not appear to line up with the weapons. This odd placement led to a recurring in-joke among fans where Claude would frequently be seen upside-down in memes and fan works. This joke was acknowledged by Nintendo and staff involved with the Fire Emblem series on three known occasions. Ippei Soeda, a character artist for Fire Emblem Heroes, posted his own illustrations of an upside-down Claude days after the box art's reveal in March 2019. Later in July, voice actor Joe Zieja hung upside-down by his feet from his back porch as he announced he would provide the English voice for Claude in the game. Nintendo of America's Twitter account later acknowledged the joke in 2020 by tweeting "Happy Birthday Claude!" upside-down and backwards.

11 days prior to its full North American release on May 13, 1997, Fighters Megamix was made available to rent early from the video rental chain Blockbuster.

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."

If the player presents the Rambley Mask collectible at the Information Kiosk, Rambley will play an audio recording of two employees (one of whom is named Jackson and is referred to as "Old Sport" by his colleague) complaining about the new mascots before deciding to quit their jobs and move to Las Vegas. This is a reference to the Five Nights at Freddy's fangame Dayshift at Freddy's, where the game's "Gnarly Ending" sees the player and Purple Guy escaping the pizzeria as it burns down before deciding to move to Las Vegas. The creator of the Dayshift at Freddy's series, DirectDoggo, acknowledged the reference on Twitter, stating he felt speechless about it.

A Japanese commercial for the Famicom release of the game features series creator Richard Garriott, appearing in his Lord British persona, for a short cameo.

The original Apple II version of the game gives the player the option to import characters from Wizardry: Proving Grounds of the Mad Overlord and Ultima III: Exodus.

Yars' Revenge began development as an Atari 2600 clone of the 1980 Cinematronics arcade game Star Castle. According to designer Howard Scott Warshaw, after he was assigned to the project, he found that a "decent version" of the game could not be made for the console. Instead, he analyzed Star Castle and took "the top logical and geometric components", or "what I thought was fun about it", and reconfigured and modified it to better suit the Atari 2600 as an original game.

The PlayStation 2 version of Dynasty Warriors 3 was the first game released by Koei to sell one million copies on a single platform; the game achieved this company record within four months of its Japanese release.

In the original Wii version of the game, there was a mechanic where defeated enemies would retain their collision for about 25 frames, a window lasting a fraction of a second. In cooperative play, this allowed for a second player to trail behind and quickly use defeated enemies as a platform, allowing for two players to traverse platforming sections without one or the other frequently dying by falling into a pit. However, for unknown reasons, this mechanic was removed in the Nintendo 3DS and Nintendo Switch versions of the game, making the multiplayer gameplay more difficult and unfair in certain sections.

The unlockable playable character Mr. Garfield is named in reference to the titular character of the Garfield franchise. Both are anthropomorphic cats, and Mr. Garfield's description simply reads "He hates lasagna", a nod to how lasagna is Garfield's favorite food.

Among the assets present in the Gigaleak, a large-scale leak of internal server data from Nintendo in 2020, are sprites for what appears to be an early version of Hookbill the Koopa with a radically different design. This iteration bears a strong resemblance to Birdo, though with numerous Koopa-like elements (including the shell, body type, and gait) that would be retained in the final game. This early design appears to explain why Hookbill the Koopa regurgitates eggs when Yoshi stomps on his head, given that spitting eggs is one of Birdo's staple abilities in the Mario series. Furthering this, some of the early sprites include ones for spitting spiked balls as an attack.

Roll's trophy contains modeled and textured undergarments beneath her dress; however, this is obscured in typical gameplay by a black void. This notably differs from Peach's trophy, which features similar censorship but has the black void baked into the model (with no additional graphics hidden underneath).