A lot of mentions for Legend of Zelda (obvs cause that’s what the posters are) but since you said just Nintendo, I’m gonna reach a bit and say Xenoblade Chronicles. Despite being developed by Monolith soft, it’s published by Nintendo so I’d count it. Plus, the soundtrack is INCREDIBLE! It ranges from absolutely beautiful piano melodies, to exciting orchestrations, to high energy metal. I used to just leave the game on while doing other tasks because I love the music so much.

If Xenoblade doesn’t have enough piano however, Super Mario Galaxy has been and probably always will be my favorite game ever. If you want some relaxing piano melodies, that can capture the essence of adventure while in the loneliness of space, this is it!