One of the biggest video game franchises in the world has a new entry.

The Legend of Zelda: Breath of the Wild finally came out on Friday for both the Wii U and Nintendo Switch, the company’s newest console.

This is big. Video games are now a $100-billion-a-year industry, growing massively over the past few years with the mainstream rise of games like World of Warcraft and Call of Duty. But it’s hard to imagine the gaming industry existing as it does today without Zelda, which has literally revolutionized gaming multiple times over several generations of games. That makes the series an important part of how roughly 1.8 billion people around the world spend at least some of their free time.

Based on the overwhelmingly positive reviews Breath of the Wild has received so far, the franchise is poised to once again change gaming. Polygon gave the game a 10 out of 10. IGN did too, calling it “a masterclass in open-world design and a watershed game that reinvents a 30-year-old franchise.” GameSpot and GiantBomb also gave it perfect scores, and Kotaku described it as “open-world perfection.” As of Friday, it’s the fourth-best-reviewed game of all time, according to Metacritic.

For Nintendo, this is an impressive — and necessary — achievement. Breath of the Wild is the big game the company has banked on to boost the initial success of its new console, the Switch. And let’s be clear: Nintendo desperately needs the win. After the Wii U failed to ever take off and the 3DS handheld console struggled to become as much of a smash hit as its predecessor, the DS, Nintendo has a lot riding on the Switch’s — and Breath of the Wild’s — success. The game is important not just to fans of the Zelda franchise, but to the health of one of the most well-known companies in the gaming industry.

To understand why, it’s important to first understand what Zelda is. While the basics of the game are clichéd — it’s fundamentally about a brave swordsman saving a princess — the series goes much deeper than that.

The Legend of Zelda is actually about a boy named Link

Zelda’s premise is one we’ve all heard before: A princess is in trouble. An evil man has captured her. And the young hero — a swordsman — is charged with saving her.

That is the basic plot outline of most (but not all) Zelda games: Link, a commoner, is suddenly thrust into a mysterious, magical quest in the kingdom of Hyrule to save the princess, Zelda, from one evil or another. Each Zelda game follows a similar arc: Link typically obtains a sacred sword, maybe collects pieces of the all-powerful Triforce (which grants wishes), and obtains other powerful artifacts to become strong enough to defeat the evil and save the day.

This plot line reflects the “legend” referred to in the series’ title — a mythology in which a hero, reborn time and time again, rises to vanquish an evil, also reborn time and time again, with the help of the powerful Princess Zelda and the Triforce.

However, some of the games in the franchise veer into different territories. Majora’s Mask, for example, doesn’t involve Zelda at all; instead, Link travels to another world that is about to be destroyed by a strange mask-wearing creature and a very angry moon. Similarly, Link’s Awakening doesn’t take place in Hyrule or feature Zelda or the Triforce.

Plot-wise, what ties the games together is a fairly absurd timeline. It’s not too important to the actual gameplay, but it’s kind of interesting to look at for superfans:

But it’s the gameplay, and not the story, that is Zelda’s biggest selling point.

Zelda has revolutionized gaming time and time again

The Legend of Zelda has defined the future of gaming multiple times in its 30-year history.

It all started with the original 1986 game, titled simply The Legend of Zelda. This was one of the biggest games for the original Nintendo system, selling millions of copies. And Nintendo knew it had something special on its hands, offering the game in a special golden cartridge unlike what other Nintendo games were sold in at the time.

While previous games had tried to blend the action-adventure and role-playing game (RPG) genres, the original Zelda was the first game to really pull it off. Consider that breakthrough RPG franchises like Final Fantasy and action-adventure series like Tomb Raider didn’t exist yet; with Zelda, Nintendo simply had the foresight to combine the elements that would go on to make these other games so good — an open world, dungeon crawling, puzzles, the feeling of “building a character” — in one package.

The open world is really what made the original Zelda stand out. At a time when technical limitations forced games to usually keep it simple, this was a game that managed to have a huge open world, letting the player navigate freely. You could even play the main levels, called dungeons, in whatever order you wanted — which was nearly unprecedented during the early era of gaming, when games were organized much more linearly. (This expansive concept was so new that Zelda was the first game to include an internal battery in the cartridge to retain save files for future play sessions, while previous games were designed to be played in a single sitting.)

Consider some of the other big hits of the time, like Super Mario Bros. It’s a phenomenal game, but it’s relatively simple: In Super Mario Bros., players mostly have a couple of major actions available to them: run and jump. With those tools, they just follow the screen from left to right to overcome obstacles, literally a straight line from point A to B. Zelda, by contrast, didn’t even have a line, letting you travel around the world as you pleased and complete the objectives of a game in a totally different order as everyone else.

This level of freedom, along with the successful action-adventure gameplay, hinted at what games could become. There are now many “open world” games, from Grand Theft Auto V to The Elder Scrolls V: Skyrim to Metal Gear Solid V, that essentially allow the player to decide how he or she will personally explore and overcome the medium’s challenges. The Legend of Zelda essentially gave birth to these concepts by letting gamers not just tackle the puzzles in different ways but also decide which levels they would tackle first.

The original Zelda achieved this so successfully that, unlike other games of the era, it’s still fun to play. As games journalist Jeff Gerstmann wrote for GameSpot in 2006, “[U]nlike some of those other NES games [rereleased since the 1980s and ’90s], this game holds up well enough to be quite playable today.”

With the exception of Zelda II (a weird 2D side-scrolling adventure game), the next few iterations in the Zelda franchise generally built on this formula, although they also moved in a more linear direction in favor of adopting more complicated action and puzzle elements. And even though the move toward linearity meant less of an open world to explore, 1991’s A Link to the Past for the Super Nintendo is widely viewed as one of the best and most influential games of all time.

But when the Nintendo 64 came along, Nintendo faced a new demand: to bring Zelda to a 3D space. This is something many gamers take for granted now, but it posed a lot of huge questions for developers at the time. How could developers translate concepts that worked well in two dimensions to three dimensions? Does the Nintendo 64 even have the tech to make an open-world action-adventure game in 3D work? How would the camera work?

It’s hard to overstate how difficult the transition from 2D to 3D was. But it was difficult enough that several beloved franchises from the 2D era, like Sonic the Hedgehog and Bugsby, never could successfully make the jump.

Then came, in 1998, The Legend of Zelda: Ocarina of Time for the Nintendo 64. The game by and large continued the formula seen in past Zelda games, particularly A Link to the Past. But by being the first game to really meld action-adventure and RPG elements in 3D, it shook up gaming. It showed that these concepts really can work in a 3D space by staying true to the franchise’s well-known sword-fighting, puzzle-solving, and dungeon-crawling elements. It also offered various technical lessons — particularly with its snappy camera controls — for other 3D games at the time. This was Nintendo skyrocketing its beloved series into a new generation of gaming.

Ocarina of Time was so successful that it is regarded as not just one of the best Zelda games but one of the best games ever. To this day, it remains the best-reviewed game of all time, according to Metacritic.

Games journalist Peer Schneider put it simply in the original 1998 review for IGN: “The new benchmark for interactive entertainment has arrived.” And Dan Houser of Rockstar Gaming, which created the incredibly popular Grand Theft Auto series, told the New York Times in 2012, “Anyone who makes 3-D games who says they’ve not borrowed something from Mario or Zelda is lying — from the games on Nintendo 64, not necessarily the ones from today.”

As Houser’s comments suggest, Nintendo’s latest outings with Zelda haven’t been as successful in pushing the industry forward. But Breath of the Wild may change that.

Breath of the Wild adopts modern game conventions while going back to Zelda’s roots

In some ways, Breath of the Wild is simply trying to bring the original Legend of Zelda to a 3D space.

Where the 3D Zelda games have floundered ever since Ocarina of Time is in their linearity. Whereas the original Zelda let you play dungeons in any order, the 3D Zelda games, with some minor exceptions, generally guided you through the dungeons in a set path. This marked an odd evolution of the franchise, given that the original Zelda was renowned in part because it wasn’t linear. But it’s a formula that Nintendo has by and large kept in the 3D Zelda games — all the way up to 2011’s Skyward Sword for the Wii.

Over the past few years, however, open world games that aren’t so linear have become huge. These games generally give you a varied set of tools and a giant playground to use those tools in, and then you decide how to take on the puzzle in front of you.

So in, for example, Metal Gear Solid V, you are given a variety of weapons and a big playing field. You then decide what to do: Are you going to work toward the main story, or are you going to do some side objectives that can earn you cash and more weapons and tools? Once you pick a mission, do you want to stealth by enemies in your way, perhaps not even killing any of the bad guys in your path? Do you want to call in an airstrike or use a bazooka, choosing a direct approach in which you brutally explode your opposition? Do you want a mix of these tactics, perhaps only using force when you’re caught? It’s really a sandbox.

This is, in theory, the direction that 3D Zelda games could have moved toward from the get-go, based on the foundation established in the original game. But since they didn’t, Breath of the Wild finally stands to fulfill that promise.

Games journalist Arthur Gies, writing in the review for Polygon, explained:

It’s debatable whether or not Zelda as a series has been in a rut, and for how long, but it’s almost certainly fallen into a predictable pattern: an overworld with dungeons that offer items, which in turn allow access to new dungeons and means of traversal. Sure, each game had its own twist — a dark world, lycanthropy, sailing, flight — but there was a predictable path for each. It was a familiar loop, and a successful one, given the series’ regard. … The Legend of Zelda: Breath of the Wild is the biggest, most open Zelda game ever made, but it also brings with it a massive change in design philosophy, and the way it treats players. Breath of the Wild is the first main Zelda title since 1991 (2013’s Link to the Past sequel A Link Between Worlds notwithstanding) to feel like it respects its players implicitly.

As Gies and other reviewers have noted, the game still has the same things that Zelda fans love: the dungeons, puzzles, items, characters, and so on. But Breath of the Wild goes back to the original Zelda’s open world, giving players the ability to decide what order they play the dungeons in and how those dungeons are approached. In fact, it is theoretically possible to start Breath of the Wild and within just a few minutes go to the very last dungeon, where the game’s big bad resides, and beat the game. (It would be incredibly difficult to actually do, since you would go into this final dungeon without any of the power-ups you earn in your typical adventure. But if you’re skilled enough, it’s possible.)

It works: Gies concludes that Breath of the Wild “establishes itself as the first current, vital-feeling Zelda in almost 20 years.”

The new Zelda game is for now the Switch’s biggest selling point, so it means a lot for Nintendo’s future

The incredible reviews of Breath of the Wild likely have Nintendo execs very excited, not least because Breath of the Wild is one of the few games that fans can expect on the company’s newly launched console, the Nintendo Switch.

This, right out of the gate, is perhaps the Switch’s biggest problem: There are very few games — a little more than a dozen, and many are remakes of old games — to actually play on the thing at launch. That makes Breath of the Wild crucial to the system’s early success, since it is the only big Nintendo game that there will be to play.

And let there be no doubt: Nintendo needs the Switch to be hugely successful. While the company is fondly remembered by many as a pioneer in the video game space, it has struggled to really build a big founding in recent years.

Nintendo’s latest home console, the Wii U, was a total dud: It was the slowest-selling Nintendo system of all time — particularly disappointing after the massive financial and sales success of the Wii, which was Nintendo’s fastest-selling home console ever. The handheld 3DS system, similarly, has struggled against competition from mobile gaming to sell nearly as much as its predecessor, the DS.

The Switch tries to appeal to all Nintendo fans by bringing together the handheld and home console markets. The system is unique in that it can be hooked up — through a dock — to a television and played from there. But it can also be pulled out of the dock and played as a handheld.

Here’s how that looks in action:

Nintendo needs this system to succeed. Consider the company’s stock: Although it grew explosively in 2007 and 2008 due to the success of the Wii and DS, it has since tanked and stagnated due to the failure of the Wii U and disappointment of the 3DS.

The Switch is Nintendo’s chance to make up for those failures. And if Breath of the Wild were getting terrible reviews, the Switch would be more likely to fail. That’s serious: If the new console doesn’t succeed, there are huge questions about what Nintendo’s future will be like. There are op-eds out there, for instance, arguing that the Switch could be Nintendo’s last console if it’s a flop. And it’s hard to discern just what the company would do in the gaming space if it left the console business.

Nintendo’s failure would be a huge disappointment for gamers. Obviously, it would affect the millions of Nintendo fans out there. But more broadly, as Zelda’s history shows, this is a company that has frequently changed gaming for the better.

Simply put, then, a lot is riding on The Legend of Zelda: Breath of the Wild — not just for the Switch and Nintendo but for the industry and gamers as a whole.