This game breaks your typical mold for a Pokemon game. The mechanics really help you feel like more of a Pokemon Trainer than any other game. Pokemon can be hostile toward players and knock you out if you don't engage them in battle, which makes encounters feel more pressured than in previous games. The ability to aim and throw Pokeballs gives a nice alternative feel from the 'push x to catch' that all the other main series games have (although, I do wish they had kept the aim and throw mechanic inside battles as well). NPC's don't seem to understand a lot about Pokemon, and that coupled with the research level of Pokemon really boosts the feeling of discovery that you get from filling out the Pokedex. They have also added in several requests from the NPC's, which can give you some goals outside of the usual fill out the dex, catch a shiny and beat the Elite 4.
Overall, I think Legends Arceus is a great stepping stone for the development of Pokemon games, and is so far the Golden Standard for Pokemon Games going forward. You did excellent, Game Freak!