Shigeru Miyamoto has been making the same request of all new employees at Nintendo for at least the past decade: For the love of all things Super Mario, please design games that might sell 30 million copies.

The request for smash hits that can generate upward of $1.5 billion sounds almost reasonable coming from Miyamoto, a smiling septuagenarian with arched eyebrows and a trove of beloved cultural properties that would make Walt Disney blush.

Despite creating mascots like Super Mario, Princess Zelda and Donkey Kong that have earned billions for Nintendo, Miyamoto dresses like a humble salaryman, wearing company merchandise beneath his blazer. He has consulted on dozens of games and was instrumental in the development of the Wii and Switch consoles, but in recent years has focused on the movies and amusement parks that Nintendo hopes will undergird its future.

“I actually don’t know why I create the things I create,” Miyamoto said through an interpreter during a private interview this week. “I’m just having fun and that is what drives me.”

He was speaking from inside the Nintendo Museum in Kyoto, Japan, an exhibition hall that opens on Oct. 2 and documents the company’s evolution from a local storefront selling handmade playing cards in the 1880s to a video game company nearly a century later.