During the development of Donkey Kong Bananza, Shigeru Miyamoto—who once created the character—playtested the new adventure. But according to producer Kenta Motokura, Miyamoto didn't get very far. Instead, he seemed more interested in smashing things than progressing through the game.
However, Motokura saw this as a positive sign. He believed that if Miyamoto had fun with that aspect of the game, then players would hopefully be curious about what else the experience had to offer.
"We had Miyamoto-san check the game occasionally. But instead of progressing through the game, he just stuck to one point, smashing and digging around a lot. It was a good thing to see him playing that way ... it proved that there are a lot of things that players could potentially be curious about in the game," Motokura said in an interview with The Guardian.
This isn't the first time Miyamoto has fixated on a single detail during playtesting. According to The Legend of Zelda: Breath of the Wild director Hidemaro Fujibayashi, Miyamoto spent most of his time climbing trees during that game's development. This led the team to add things for players to discover in trees and throughout the world to encourage exploration. Miyamoto, however, ignored all that—and just kept climbing.