I don’t have time to look it up right now, but I’ll edit this comment later today with a few videos that go into the specific graphical techniques Nintendo used to make Wind Waker and Super Mario Galaxy look so good

edit: idk if editing and tagging in a reply works, but @regul@hexbear.net, here are the links I mentioned:

How The Wind Waker Redefined Cel Shading

How scrolling textures gave Super Mario Galaxy 2 its charm

If you enjoy those videos, definitely check out the longer videos as well as the shorts on that channel.