* The tune that plays whenever Troff and Scoff open a boss door is actually from ''VideoGameVideoGame/BanjoKazooie'', where it plays whenever Banjo enters an area containing a Stop 'n' Swop item. Part of it also sounds like the tune that plays when Dingpot fills all of your items in ''VideoGame/BanjoTooie''; worth noting is that this theme still predates ''Donkey Kong 64'', as it was DummiedOut of ''Banjo-Kazooie''.
* There is a 5-Banana Coin in Fungi Forest that went undocumented (though several people had already collected it many years before by purely goofing around near the nearby DK barrel, not thinking much about it, if the Website/YouTube comments on several videos about this are of any indication) until January 28, 2017, seventeen years after the game's release. The collectible was found when Istorage, a member of the game's speedrunning community, datamined the game and found data for a 977th 5-Banana Coin located here; prior to his findings, it was assumed that there were only 976 of them in the game. The coin in question can be found in a dirt patch hidden in a patch of tall grass surrounding the DK Barrel just outside one of the mills.
* GenreKiller: Depending on who you ask, it killed off the [[GottaCatchEmAll collectathon]] [[PlatformGame platformer]] because OneHundredPercentCompletion took so long that most people who managed it had had enough of that style of gameplay to last for years, or it killed the genre by causing people to get completely sick of it.
* KeepCirculatingTheTapes: For many years, fans were left speculating as to why Nintendo hadn't rereleased this game on the Virtual Console. While Nintendo, not Rare or Microsoft, owns the rights to the game because they created Donkey Kong, many speculated that the inclusion of Jetpac, an original Rare IP that is now owned by Microsoft, prevented the game's re-release. However, Nintendo finally rescued the game in April 2015 when it was announced it as one of the first [=N64=] games to hit the Wii U Virtual Console.
* NamesTheSame: ''[=DK64=]'' level "Crystal Caves" shares a name with a song in ''[[VideoGame/YoshisIsland Super Mario World 2]]''. [[ExactlyWhatItSaysOnTheTin That plays in cave levels.]] Same goes for the mini-game "Stealthy Snoop" sharing the name of a song in ''VideoGame/PaperMario64'', where Peach sneaks around the castle. Finally, Mad Jack shares his name with the eponymous protagonist of ''WesternAnimation/MadJackThePirate'' (ironic- ''Mad Jack the Pirate'' aired on Creator/FoxKids, while the ''WesternAnimation/DonkeyKongCountry'' cartoon aired on what was then [[Creator/ABCFamily Fox Family]]).
* ThrowItIn: The DK Rap was originally written as a joke by Grant Kirkhope, but the developers liked it enough to include in the game.
** Several, the most notable being an inaccessible room in Creepy Castle with a glass wall. If you stand on the hallway outside of it and use a first-person perspective, you can see a tall, carved stone pillar with a Monkeyport (teleportation) pad for Tiny nearby as well as a purple banana balloon floating over it. The room appears to be useless. King K. Rool's control room also features five steel kegs with the Kongs' faces painted on them. Probably nothing more than a little detail, but it sparked some speculation back in the day.
** The fact that this was the first Donkey Kong game since ''VideoGame/DonkeyKongCountry1'' not to feature a Lost World sparked a lot of urban legends back in the day.
** Some text in the game's coding and an [[https://www.youtube.com/watch?v=kOAATfDXfuY unused cutscene]] suggest that this could've been compatible with ''[[VideoGame/BanjoKazooie Banjo-Tooie]]'''s scrapped Stop 'n' Swop feature.
** Fungi Forest was going to appear in ''Banjo-Kazooie'' as Fungus Forest, but the level was (among other levels) scrapped from that game due to time constraints.
** The game as a whole was initially planned for the 64DD add-on, but repurposed for cartridge after that peripheral's failure.
** If one uses ''[[VideoGame/GameShark GameShark]]'' to put the [[CompetitiveMultiplayer multiplayer]][[BonusMaterial -only]] [[SecretCharacter character]] Krusha into the main game, he will be referred to by name from the [[NonPlayerCharacter NPC's]], and will have a few animations that he never uses in multiplayer. Whether this means that he was intended to be usable in singleplayer mode at some point or not is unknown.
** Snide's original reason for betraying K. Rool was that he was always given menial chores to do, and was turned down when he asked to work on the Blast-O-Matic.
** Early in development, the game was intended to combine TwoPointFiveD and linear 3D segments, in what the development team later described as a mix of ''VideoGame/YoshisStory'' and ''VideoGame/CrashBandicoot''. Neither Nintendo nor the Rare higher-ups much liked this gameplay style, however, and so the development team were told to scrap everything they had done and remake the game along the lines of ''VideoGame/BanjoKazooie'', Ironic seeing that Banjo-Kazooie was going in the same gameplay direction at an earlier point and the franchise went down that direction in ''VideoGame/DonkeyKongCountryReturns''.