>>35994026100 new Pokemon at least. Including cross gen evos.
Megas of mons that need it as well as popular ones. Mega stones are manmade in this universe and were created for competitive use to make more Pokemon viable.
New Z Moves.
Keep the old EXP Share, but you can adjust which mons in your party get the boost. Mons under its influence cannot be boxed until it is turned off.
No new types.
The legendaries are like RBY and DPPt, not part of the story but you hear about them and encounter them in postgame.
Have Ace Attorney like investigation avaliable in specific areas (like Pokefinder) where you can use the Switch's gyroscope in handheld mode to look around. Also lets you look at landmarks etc in detail.
Plenty of postgame cases for you to solve on the level of Delta Episode/Looker postgame. DLC too.
Battle Frontier type place with facilities that really shake up the rules. Inverse facility, perma Trick Room facility, one with minigames that change the state of your Pokemon before battle. Etc. Lots of fun.
Evolution can happen mid battle.
You can change what battle music plays during wild/trainer/gym battles at any time in the options menu but you have to have encountered that track first. After completing the game you unlock a ton of remixes of old game battle themes including spinoffs.
Postgame areas lime DPPt/BW2 with additional gym challenge areas run by old Pokemon characters.
Each challenge area has some secret areas unlocked in postgame with rare items/old characters to battle/legendary Pokemon from past gens
Bring back hordes. No more SOS. But dont make hordes that can attack their own allies. Keep the in PC IV judge. Basically combine breeding from SM with EV training from XYORAS.
