It has been confirmed that Pokémon Legends: Arceus will not be an open world game and that it will be closer to the Monster Hunter series than The Legend of Zelda: Breath of the Wild, in terms of its gameplay style. Pokémon Legends: Arceus is an upcoming RPG that is set in the Hisui region, which is the ancient version of the Sinnoh region from Pokémon Diamond and Pearl.
The original trailers for Pokémon Legends: Arceus showed a game that was more akin to Breath of the Wild than the regular mainstream Pokémon games. The player was shown exploring the wild frontier of the Hisui region, with Pokémon wandering around on the world map, in a similar manner to the Wild Areas in Pokémon Sword and Shield. The Hisui region is guarded by Noble Pokémon, which are akin to the massive elite monsters and bosses seen in Breath of the Wild.
The gameplay style in Pokémon Legends: Arceus won't be as free-roaming as the original trailers suggested. In a statement made to Kotaku, The Pokémon Company confirmed that Pokémon Legends: Arceus won't be an open world game. Instead, the gameplay will feature a mission/level-based structure.
"In Pokémon Legends: Arceus, Jubilife Village will serve as the base for surveying missions. After receiving an assignment or a request and preparing for their next excursion, players will set out from the village to study one of the various open areas of the Hisui region. After they finish the survey work, players will need to return once more to prepare for their next task. We look forward to sharing more information about exploring the Hisui region soon."
The gameplay style in Pokémon Legends: Arceus is going to be closer to the Monster Hunter series than an open world game. In the Monster Hunter games, the player has a hub area, where they can create gear and prepare meals that add buff effects during hunts. The different hunts send the player to a specific location, where the monster they are seeking is prowling the land. It seems that Pokémon Legends: Arceus will have a similar design, with Jubilife Village being the hub, and the different areas of the Hisui region acting as stages.
It's possible that this design choice was a result of the technical limitations of the Nintendo Switch. Breath of the Wild managed to pull off an open world, but it has been proven in the past that Game Freak has struggled to do similar things with the Pokémon games. The vanishing/appearing Pokémon on the overworld (especially in the Wild Areas) in Pokémon Sword and Shield is a testament to that. The level structure never diminished the fun in the Monster Hunter series, so there's no reason why Pokémon Legends: Arceus won't be just as enjoyable. It's just a shame that the player won't be able to truly explore the Hisui region, in the same manner as Hyrule.
Pokémon Legends: Arceus will be released for Nintendo Switch on January 28, 2022.
Source: Kotaku