At the start of the game you can choose between 3 different levels, not sure how it works but seems promising

Zacian and Zamazenta after you save them of a new thing called "darkness" will cooperate with you to defeat Eternatus in an epic battle with just the legendary Pokemon in your team

The 8 gyms in order are grass, water, ice, fairy, ground, poison, electric and steel

There is a new legendary Pokemon trio, pretty similar in design to the symbols on Kalos league room, they're like guardians with armors, can't remember the types

Dynamax seems to lag a bit the game at the start when it's used but it gets better quickly

Elite Four types are fire, ghost, bug and rock , champion is dragon type but with a lot of variety

There's a part in the game where you need to fight in a train to team Yell, cause they're trying to crash it, at the end of the train you will fight a team Yell administrator, kind of a crazy doctor that uses psychic Pokemon and a new psychic/poison one pretty similar to a doctor with lot of potions and things that he throw in the air

Wooloo evolve into a serious sheep, keep normal type, Corvyknight doesn't evolve, I saw new Pokemon like a rock type one that seems inspired in a catapult and jump between catapult, a ghost/steel type that seems like the ghost of a queen with lot of jewels and a kind of diva pretty similar to Meloetta but bigger that fairy gym leader use as her main Pokemon

Galar new Pokemon are around 100, not sure if I miss the count but not less than 100 I could say

A lot of new evolutions to past Pokemon, Eevee gets a new steel evolution, Roselia gets a new alternative evolution with beautiful design as Roserade but with lot of knifes switching the flowers being grass/steel, Smeargle evolves into a big one and fluffy but keeps normal type, and there are more but I can't remember every new evolution right now