Comment by dmonitor
GMTK is popular, but he's mostly talking out of his ass. He's got zero industry experience and most gamedevs I know personally clown on his takes constantly. Unless he references specific Nintendo interviews where they talk about their design process, I have doubts about this video containing an accurate description of how Nintendo does things.
At least in this video, all the interviews and documents that they base their claims/opinions on are listed in the description, so you can easily also peruse them if you doubt the interpretation.