There's a few changes and additions that are improvements over previous Pokemon games, but everything else is just worse. It looks terrible, it plays terribly, it's laggy, there's no danger in the story, nothing impactful happens, the Tera "powerups" are time consuming unskippable animations and uninteresting, I could go on and on about how terrible this game is. It feels like most of it is the fault of the Switches hardware limitations, but stuff like the Tera transformation has nothing to do with that either.