Open-world games have become popular in recent years, and many developers are making the move to more expansive, less linear gameplay. While the traits that make a game "truly" open world are arguable, the main idea of open world is that the game's map is large and explorable. The player has the autonomy to go nearly anywhere they want, and the player can also pursue side content without being limited to a linear track.
Nintendo has joined the trend, testing the new gameplay styles for their biggest franchises. Judging by the generally positive reception to these games, it seems likely that Nintendo will continue to use open-world maps in new games. Games like Super Mario Odyssey and Breath of the Wild were major hits, and players often cite the autonomy and open exploration as high points.
Super Mario Odyssey is perhaps the first "true" form of an open world in the Mario series. Some argue that Super Mario 64 is an open-world game, while others state that the N64 title is too limited to be called such. Super Mario Sunshine has similar discussions surrounding its status as open world. Super Mario Odyssey, however, has the largest world out of any Mario title, and the many kingdoms, side quests, and sandbox-style gameplay gave players a lot of autonomy in how they played the game. Odyssey was massively popular and critically acclaimed, so it's no surprise that more games followed its lead.
Nintendo returned to open-world gameplay with Bowser's Fury, part of the 2021 re-release of Super Mario 3D World. While it's not as extensive as Odyssey, Bowser's Fury also offers a 3D open world. The game itself is relatively short, but players have plenty to explore in the world map, take snapshots in-game, and collect all of the stickers.
While the Legend of Zelda games have always taken place in big, elaborate settings, Breath of the Wild was the first title in the franchise where exploration took precedence over the main storyline. While fans did enjoy the game's narrative, many players spent most of their time collecting resources, cooking, and exploring the lush Hylian landscapes. Players could sink many hours into the game without setting foot in the main plot. The exploration experience was rewarding, and players felt like real adventurers. Any landmark could be reached if it was visible. The switch to open world felt very natural for the franchise, as the fantasy setting has always been grand in scale.
Breath of the Wild will be receiving its own sequel on the Switch, though its exact release date is unknown. Not much is currently known about the sequel, but it is highly anticipated by fans. The new game will likely add even more to an already extensive world, and give players more tasks to pursue on the side during the main plot.
The Pokemon series has historically been very linear in how players get around the world, with the same approach to towns, routes, landmarks. and more. Exploration typically has not been a major focus point for the franchise, but Sword and Shield's region of Galar expanded the world to a larger scale with the Wild Area, which connects to several cities and is a wide open space with few restrictions. The decision to have Pokemon visible on the map rather than solely hidden to random encounters also brought more of an open world style to the gameplay.