First up, some name changes. As the trailer notes, you’ll be exploring the Hisui region. It’s not a new region, but rather the old name for the region that will be known as Sinnoh in the future. The game does take place long before the modern day setting of the series, after all.
But even as a pseudo-new region, this means new regional variants for existing Pokemon. The Pokemon Legends: Arceues shows of a few of that, as well as new evolved forms for already established species. And then there’s the open world stuff. As we’ve seen before in previous trailers, you can capture wild Pokemon without engaging in battle. Though you can choose to throw a Poke Ball with your Pokemon in it, which then starts the battles. Even these are a little different, as attacks can now be augmented in Agile and Strong styles. The former lets you attack multiple times in a row for less damage each, while the latter increases a move’s power at the cost of speed. Your Pokemon’s stats also do more in Pokemon Legends: Arceus; a critter with high Speed stat mat actually attacks multiple times in a row, even without Agile style. The stronger ones will actively seek you out to attack you, so the old formula of weakening them via battles will still play out. Though before that happens, you can actually perform dodge rolls that’s very reminiscent of an action RPG, quite unlike the usual formula of the series. Overall, Pokemon Legends: Arceus is shaping up to be a really good entry into the series. It’s adding meaningful additions to the old formula that’s getting a little stale, while also (hopefully) moving away from the silly extra-dimensional Ultra Beast stuff. The game is scheduled for a 28 January 2022 release for the Nintendo Switch, which may actually be a good time to get one if you don’t already own it. (Source: The Pokemon Company [1], [2])