When Super Mario Bros. hit shelves, video games were in dire straits. Revenues were down nearly 97%—from $3.2 billion in 1983 to $100 million in 1985. Atari, which not long before had been the fastest growing company in U.S. history at the time, had filed for bankruptcy. And mall arcades were moving past their heyday.

But the emergence of the game featuring the spunky plumber on Sept. 13, 1985 captured people’s interest—and Nintendo’s NES became a hot seller. And as Super Mario Bros. celebrates the 30th anniversary of its Japanese release this weekend, the game remains entrenched as one of the most heralded—and best selling—titles of all time.

Life to date, Super Mario Bros. has sold more than 40 million units, according to Nintendo (NTDOY). (And 2009’s new take on the game—New Super Mario Bros. U—has sold more than 10 million.)

It’s one of six inductees in the World Video Game Hall of Fame, And it’s the game that truly introduced the world to Shigeru Miyamoto, who has gone on to create several more of Nintendo’s most iconic franchises, including Star Fox and The Legend of Zelda.

“Mario is, by far, the single largest video game property ever,” says John Taylor, managing director at Arcadia Investment Corp. “It’s where you start in scaling the size of the market globally for games.”

Super Mario Bros. wasn’t the first game to feature Mario. He technically was born in 1981 in the Donkey Kong arcade game. But at the time, he was only known as “Jump Man”—and his iconic moves were rudimentary. It was Super Mario Bros. that gave him an identity and made him an icon. To date, the character has appeared in over 200 games, according to Nintendo.

Miyamoto says the game was designed to let encourage exploration. It shipped with no instructions or tutorial, but it’s a title most new players quickly understand, regardless of their history with video games. And the more players explore, the more surprises they’ll find. (Think, for instance, how counterlogical it was 30 years ago to jump in the air and knock your head against a brick, only to be rewarded with a coin or mushroom that made you double in size.)

What’s especially impressive about Super Mario Bros., though, is how it has endured over the past 30 years. This is the game that set the tone for many future Mario titles.

“Mario introduced a style of imaginative and delightful gameplay, which really hasn’t changed all that much in the three decades it has been out there,” says Taylor. “You could argue that the basic design is like the basic design for Monopoly. It doesn’t change—and yet people keep playing and playing. There’s something about the little surprises. There’s something about the quirky music. There’s something about the overall experience.”

As Super Mario Bros. hits this momentous anniversary, Nintendo is once again calling on the game to help it out in a very crowded holiday market. On Sept. 11, the company will release Super Mario Maker for Wii U—a title that lets fans try their hand at creating levels in Super Mario Bros. (along with Super Mario Bros. 3, Super Mario World, and New Super Mario Bros. U.), then play them themselves and share with friends.

It’s expected to be the biggest game of the year for Nintendo.

As for Miyamoto? He’s head down overseeing development of Star Fox Zero, another holiday release. And while he says he does plan to observe the anniversary of Super Mario Bros., which he says remains the game he’s most proud of, he’ll do so in a low key fashion.

“I really don’t want to get any fatter, so I probably won’t have any cake that day,” he told Fortune with a laugh earlier this year.

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