I've known this for about a year and a half now, but I still find this fascinating nonetheless. It's worth noting that in the ROM, the internal names for the Funky mini-games are referred to as Cobra Tracks (e.g. Cobra Track 0, Cobra Track 1, etc., all the way up to Cobra Track 4), which is an obvious reference to Cobra Triangle (see here:
https://tcrf.net/Donkey_Kong_Country_3: ... Debug_text )
I guess I shouldn't be surprised that Rare recycled stages from an old NES game for the mini-games in DKC3... it makes me wonder if the other mini-games in the DKC games for GBA were recycled from some other game. For example, are Funky's Gyrocopter mini-games from DKC2 GBA original or recycled?
(By the way, I played Cobra Triangle for a brief period of time and found it really hard! Like in the video, I also struggled with the level where you have to rescue the Kongs nameless people from the Kremlings enemy boats. It's about as hard as other NES games of Rare's like Battletoads! This is in part due to limited lives and continues...)