Even if you spent hours with the iconic gold cartridge loaded into your NES, you can probably still learn a few things about Link’s epic adventure.

1. NINTENDO DIDN’T THINK THE GAME WOULD BE POPULAR IN AMERICA.

Although The Legend of Zelda had garnered positive feedback in Japan, Minoru Arakawa, the president of Nintendo’s American division, expressed doubt that U.S. players would have the patience for such a complex and challenging game. Arakawa was particularly concerned over the text-heavy game’s reliance on its players’ willingness to read!

2. THE STORY WAS INSPIRED BY ITS CREATOR’S CHILDHOOD.

Game design icon Shigeru Miyamoto borrowed from his own history to dream up Hyrule, the setting of The Legend of Zelda. He developed the game’s enchanted forests while thinking of his youth in a small village near Kyoto, where he spent much time exploring the nearby woodlands. Moreover, Miyamoto modeled the puzzling nature of Zelda’s many dungeons on his maze-like childhood home, which was riddled with indistinguishable paper doors.

3. IN SOME WAYS, ZELDA WAS DESIGNED AS THE “ANTI-MARIO.”

You might be familiar with another Nintendo game that hit American shelves just a few months before Zelda: Super Mario Bros. The company, and in particular designers Miyamoto and Takashi Tezuka, developed the original Zelda and Mario outings simultaneously, working hard to ensure that the two felt very different. Where Super Mario Bros. was in every way a straightforward mission, Zelda was meant to confuse and provoke creative problem solving.

4. PRINCESS ZELDA HAS A FAMOUS NAMESAKE.

Despite being conceived in Japan, Zelda’s titular princess was named after a native Alabaman. Miyamoto confirmed that Zelda Fitzgerald—novelist, feminist, and wife of F. Scott Fitzgerald—was the inspiration for his Hyrulian heroine’s handle.

5. THERE IS SIGNIFICANCE TO LINK’S NAME, TOO.

Originally, The Legend of Zelda was meant to be a game that spanned in-universe time periods, beginning in the canonical “past” and ending up in the “future,” with the Triforce acting as a mode of transport between them. The series hero’s unusual moniker was meant to symbolize his role as a link between the eras. But Nintendo’s current position is that he is a “link” between the player and the game.

6. SEVERAL OTHER ELEMENTS WERE DROPPED FROM THE ORIGINAL VERSION OF THE GAME.

Early incarnations of The Legend of Zelda were intended to include the option to design your own dungeons (ultimately scrapped when Nintendo realized that navigating existent dungeons was a lot more fun than building ones from scratch). Additionally, the original Japanese version of the game opened with the player receiving his or her sword outright, as opposed to earning it upon completion of an early cave level.

Another element that did not carry over to American game play from the Japanese version of the game was the inclusion of a working microphone. The device famously came in handy in defeating an enemy called Pols Voice, a rabbit-like ghost that inhabits several dungeons. The microphone, as suggested by the game’s instruction manual (which stated that Pols Voice “hated loud noises”), allowed players to defeat the creature. Without the availability of this option on the American console, however, the manual’s aforementioned tip was simply confusing.

7. MIYAMOTO TOOK AWAY THE SWORD AS “PUNISHMENT” FOR GAMER COMPLAINTS.

When Miyamoto caught wind that early test players were disgruntled by confusing game play and unclear objectives, he decided to up the ante by forcing players to earn Link’s sword via triumph over a complicated cave level before beginning the adventure in earnest. Miyamoto predicted that such a mystery would give a clear first mission and prompt communication between individual players, with successful strategies spreading by word of mouth.

8. THAT SAID, YOU DON’T ACTUALLY NEED THE SWORD TO COMPLETE MOST OF THE GAME.

Technically, you can get through the bulk of The Legend of Zelda without use of Link’s sword. The only component that requires its use is the final boss battle against Ganon, who can only be harmed by this weapon.

9. THE GAME SHARES ELEMENTS WITH A FEW OTHER FAVORITES.

Although Miyamoto toiled to keep The Legend of Zelda and Super Mario Bros. as distinct as possible, there is at least one minor example of crossover. The “Piranha Plant” enemy best known as the pipe-dwelling pest that litters the original Super Mario game (as well as most subsequent games) rears its head at a few points in Zelda.

Zelda returned the favor to the Mario franchise, lending Super Mario Bros. 3 the sound effect for its world-hopping magic whistle. The sound was developed in association with the recorder device found in The Legend of Zelda.

10. THE TRIFORCE IS MODELED AFTER THE JAPANESE SYMBOL MITSUUROKO.

Present in every Zelda game, the three-triangle symbol is actually modeled after the emblem of the Hōjō clan, a tremendously powerful family in 13th- and 14th-century Japan. The emblem was known as the Mitsuuroko, which translates to “the Three Dragon Scales.”

11. NINTENDO ALMOST WENT WITH A DIFFERENT THEME SONG.

The game’s creators originally intended to use French composer Maurice Ravel’s composition Boléro as the score for the game, but Nintendo couldn’t nab the rights to the number. As such, brilliant in-house composer Koji Kondo whipped up what is now one of the company’s most beloved tunes.

12. EVERYONE WHO WORKED ON THE GAME WAS CREDITED UNDER A PSEUDONYM.

Well, except for executive producer Hiroshi Yamauchi. It was not particularly uncommon practice at the time for game designers in Japan to receive attribution via moniker as opposed to their proper names, due to companies’ fear of talent poaching. Miyamoto is credited as “S. Miyahon,” Tezuka as “Ten Ten,” Kondo as “Konchan,” and programmer I. Marui as “Marumaru,” among others.

13. THE DUNGEONS FIT TOGETHER QUITE NEATLY.

Every dungeon in Zelda’s main quest bears a distinct shape, generally befitting that of its namesake (i.e., “The Lion” is shaped like a lion). That said, all nine dungeons, when fit together onscreen, add up to a perfect rectangle. This isn’t simply a nod to Nintendo’s particularly anal-retentive players, it is a means of compacting console data.

14. ZELDA WAS THE FIRST GAME TO FEATURE A COMPLETE “SECOND QUEST.”

While other games, particularly Super Mario Bros., offered the option to replay a more difficult version of the same game that differed only in details like the number of villains populating levels, Zelda was the first to offer a completely different second terrain on the same cartridge. You don’t even have to beat the game to access “Second Quest.” You can reach it immediately by naming your game play file “Zelda.”

15. SOMEBODY BEAT THE WHOLE GAME IN HALF AN HOUR.

On February 27, 2015, a user known as “Lackattack24” completed the entirety of The Legend of Zelda (minus the “Second Quest”) in 30 minutes and six seconds.