So, I decided to check the menus through videos, and in 3D World menu, there was no Luigi Bros. game (the one game added if you had the NSMBU's Luigi U DLC).
Hi! I had a few experience extracting contents of the Switch games that I owned. But just recently, I bought Fire Emblem: Shadow Dragon and the Blade of Light (for those who don't know, it was the first Fire Emblem game on the Famicom except it was English localized).
But anyways, I bought it...