Your rival is named Hop, but you will also be facing of against Bede and Marnie

Team Yell is the gang in this game, who are well meaning fans of Marnie causing trouble

To become part of the gym challenge, you will have to get an endorsement. Bede gets an endorsement from Chairman Rose and his secretary Oleana

Eternatus is the evil legendary. The other legendary will be a wolf, who will either have a shield mane or hold a sword like Great Wolf Sif. Don't recall its name

Dynamaxing and Gigantamaxing are new dynamics that will supersize pokemon in specific areas. Gigantamaxing is different from dynamax as it changes what the pokemon looks like. Meowth looks like long cat. Lapras gets layers like musical bars to its shell and musical notes. Pikachu looks like retro fat pikachu

Sonia is Leon's former rival who is researching the dynamax phenomenon at the behest of her grandmother and professor of the game.

Some pokemon, like Farfechtd, will get regional evolutions, like Sirfechtd. Meowth looks like a ball of spiky grey fur

Skwovet and Greedunt iirc are chipmunk pokemon who will hide in berry trees and attack randomly if you shake for too many berries. If they attack, you lose half the berries that dropped.

The fourth gym is the first Fairy type gym, led by an actress named Opal. Milo, Nessa, and Kabu are the first ones.

Before fighting the gym leaders, you have to complete the gym challenges.
- Milo has you herding sheep pokemon named Wooloo, but Pamper, electric corgi pokemon, will startle them and send them rolling elsewhere.
- Nessa has you running through a maze where water blocks the way
- Kabu requires you to catch pokemon and get 5 points, but you have to be in a party battle with another trainer who's also trying to catch it

While there is a transit system, you will have to go through the Wild Area at times, an open world biome that has a weather system and little pockets where wild pokemon dynamax and have to be beaten in a for person raid. You will randomly see nearby players and interact with them to get their league cards and items

Camping is how you play with pokemon now. You'll get two toys, a feather toy and toy pokeball, which can raise friendship. You can make curry which will raise starts and friendliness

Pokémon will not walk beside you in the overworld map

Scorbunny will have fighting moves, but is pure fighter. It becomes Raboot, but I don't remember the final evolution, except that it looks like a fighter. It looks humanoid

Sobble becomes Sizzile and then Intelleon, a chameleon with a spy theme

Grookey will end up as a giant gorilla that beats a wood drum to attack.

The pokedex will have somewhere around 600 pokemon

There's a lot I'm missing, but I wasn't planning on leaking until now. I'm angry and upset, and while I liked what I saw, I didn't get too far.