There is an unused audio clip of Captain Falcon saying "Come on!" and "Blue Falcon". The Blue Falcon is Captain Falcon's final smash in Super Smash Bros. Brawl, and both voice clips appear in that game. It's possible the developers were experimenting with final smashes, just as they did in the original Super Smash Bros.

The bonus for getting a Star KO on all of the opposing team's members is called "Rocket KO". This may be a reference to Team Rocket from the Pokemon TV show, as they are commonly seen blasting off into the sky, punctuated by a star glint.

Like the original Ice Climber, Topis were changed from seals to a yetis due to the controversy of seal clubbing. Oddly enough, the English trophy description is exactly the same as in the Japanese.

When the game was revealed during E3 2001, the game's introduction sequence was played, followed by gameplay footage demonstrating each character's movesets. The only changes made when adding this into the game was to the gameplay footage.

In the PAL version of the game, the Rainbow Cruise stage is renamed to "Rainbow Ride", likely for consistency with the international versions of Super Mario 64.

A segment of the remixed DK Rap used in the Kongo Jungle stage has the Character Select theme from the original Super Smash Bros. mixed into it.

In a prerelease build, the "Temple" stage originally had an elevator that led to the bottom of the stage, and had a fixed appearance. Players could also walk through the laboratory in Great Bay. Hyrule Temple had two mysterious platforms in the center of the stage. These platforms can also be seen in the game's Special Movie.

The last sentence of Pit's Trophy description reads, "Will Pit ever fight again?", possibly foreshadowing his role as a playable character in the next entry of Smash Bros. released 7 years later, Super Smash Bros. Brawl.

In the Mushroom Kingdom stage, pausing the game and looking off to the left or right of the stage to see outside of the standard gameplay field of view, it's possible to see walls with warnings signs reading "Danger" on them, warning the player of the stage's boundary. Despite the Mushroom Kingdom stage having a different design in Super Smash Bros. Melee, these signs still appear in the stage.

Mr. Game & Watch's move set represents at least 19 separate games, all of which have been re-released at least once on the Game Boy or DS.

8-Player Smash (a mode introduced in Super Smash Bros. for Wii U) was originally planned for this game. However, due to technical performance, Sakurai stated "it was more than impossible."

The reflections found on the Fountain of Dreams and the models inside the magnifying glass when a character is offscreen are not actually the character's model, but rather a low res version of the model. These versions of the models don't show any item the character is holding, nor do their facial expression change.

Roy's belt buckle has the image of a lion on it. This is likely a reference to his endgame title of "Young Lion" in Fire Emblem: The Binding Blade. He was also referred to by this title in the Fire Emblem Awakening DLC.

The only fighter who didn't make their playable GameCube debut in this game is Luigi, who was previously playable in Luigi's Mansion.

While almost every character requires eight frames after grabbing onto a ledge before they can do anything, Link is the only character that requires four frames before performing another action.

There is an unused sound of the Boo's laugh from Super Mario 64 with the file name ST_GREATBAY_TKLE_LAUGH which would've likely been used for Tingle at the Great Bay stage.

In the game's files is an unused sound for when you get a Rare Trophy. This sound would later be used in Brawl, and as part of the character unlock screen in the subsequent three installments following said game.

When the game was rereleased under the "Player's Choice" banner in the US, the color of the game's title on the spine was inverted.

If you turn off the music and select Captain Falcon on the character select screen, an extremely faint grunt obscured by the Announcer saying Captain Falcon's name can be heard. In the game's sound test, audio files can be found with "DEMO" attached at the end of them showing that every character in the game had similar planned sound effects on the character select screen, but only Captain Falcon's sound remains audible. Additionally, in the game's files, animations labeled "Select" and "SelectWait" can be found for every character in the game, many of which were either ripped directly from Super Smash Bros., are unfinished, or were repurposed in the final game. These are all presumably remnants of an earlier version of the character select screen that more closely resembled Super Smash Bros., where the character's in-game models were visible and used special animations and sound effects when selected.

In an animated trailer for Boktai: The Sun Is In Your Hands!, a boy can be heard playing Super Smash Bros. Melee on a Nintendo Gamecube.