When Pit gets Star KO'd, he'll shout out that he never learned how to read. This is likely a reference to a scene from Kid Icarus: Uprising Spoiler:when Palutena cuts off his power of flight upon defeating Pyrrhon.

Despite appearing in the box art, the Triceratons do not appear in the game itself.

While in an interview with Valve News Network in February of 2018, Gray Newell (Son of Gabe Newell) revealed that the final boss of Half-Life, the Nihilanth, represented him as a baby, stating "The Final Boss of Half-Life 1 actually the 'giant evil baby monster' is supposed to be me. When my mother was in childbirth they were thinking 'what's something really scary,' and at the time, having a child seemed to be the most scary thing to everyone."

In an Dengeki and Marukatsu Megadrive magazines interview, game's graphic designer Toshio Yamamoto stated that his team didn't use a planning document for the game.

Makoto was originally planned to be introduced in "Street Fighter III 2nd Impact: Giant Attack", but time restrictions led to her not being included.

During development, Ayla's animations sported bouncier breasts, but this facet of her animations was toned down before release.

The moon has a 3d model in the sky that is illuminated by the sun's direction to show accurate phases during gameplay.

Skate/Sammy was originally planned to wear roller skates, but they were replaced with roller blades due to their popularity at the time.

The Japanese Arcade version has Pac-Man wearing a hat with a feather through it.

In the American arcade version, Pac-Man's has was changed to resemble the one he wore in the Pac-Man cartoon from 1982.

An early unpolished draft of Penny’s intro cutscene is present in the game files.

Unused Game Center graphics can be found in the PC version's data. Only iOS and MacOS devices have this feature.

An unused version of one of the cutscene images can be found in the DS release's files. The Ivory-Billed Woodpecker's name is off-centered, but is otherwise mostly the same.

If the Player backtracks at a certain point in level 4-3, The Amiss Abyss level, and waits a while they can see a one of the eponymous creatures of the Metroid Franchise floating in the background in silhouette.

This is true in both the Wii U and Nintendo Switch versions of the game

The game is called "Holy Magic Century" in Europe and "Eltale Monsters" in Japan.

In 2018, former game director for Star Wars: The Old Republic, James Ohlen, said in an interview with GameInformer that he regretted having not pushed it to be "Knights of The Republic online" as opposed to making it traditional in the style of World of Warcraft, referring to it as "Star Wars World of Warcraft."

In an early announcement trailer for the Nintendo Gamecube, Animal Crossing was called (or at least promoted as) "Animal Forest for Nintendo Gamecube", outright referencing the original Japanese title of the game (Dōbutsu no Mori or "Animal Forest" in English). This suggests that either the English localizers were thinking of keeping the game's original title, albeit translated, or the title "Animal Crossing" was not yet finalized.

As of the 4.0.0 Update, which originally brought USB headphone support to the Switch, it was discovered that, via the use of the Wii U's Gamecube Controller Adapter, that almost every Switch game can be played with a Gamecube Controller. However, since the Gamecube Controller lacks a left Z-button the player does not have access to all of the controls of games that normally would utilize the Switch's ZL button.

A PlayStation release was planned and almost finished, however the game was cancelled because it didn't meet EA's standards.

According to Chris Glass, a member of the game's development team, the texture used for the bark on tree trunks is simply a green-tinted photograph of feces.

Bubble Bass has unused eye textures in the GameCube, PlayStation 2, and Xbox version's files, suggesting he may have been planned to have a larger role in the game.