PaperSplash
Goomba
It's not a translation quirk or anything; they're called "courses" in Japanese as well (コース, which is a loan word from English). But clearly even Nintendo's localization teams find this a weird word choice; in the English version of Super Mario Maker 2 there's a bunch of jokes about Nina getting the terminology wrong and most other localizations opt to call them "levels" regardless.
It does makes sense that they wouldn't use "level" originally though as Japanese game terminology tends to favor "stage" (ステージ, again directly borrowed from the English word) for that context, with "level" (レベル) in the context of video games being more associated with the RPG mechanic over there. But "course", as far as I'm aware, is not an established gaming term in either language.
So with all that in mind, why did they go with "course" over something like "stage"? Did they just want a unique franchise term to stand out, like how Sonic has "zones" and "acts"?
It does makes sense that they wouldn't use "level" originally though as Japanese game terminology tends to favor "stage" (ステージ, again directly borrowed from the English word) for that context, with "level" (レベル) in the context of video games being more associated with the RPG mechanic over there. But "course", as far as I'm aware, is not an established gaming term in either language.
So with all that in mind, why did they go with "course" over something like "stage"? Did they just want a unique franchise term to stand out, like how Sonic has "zones" and "acts"?