This information comes from CoroCoro…
– You follow Entei, Suicune, and Raikou around Johto, just like in the original games. However, Eusine is stalking Suicune.
– Ho-Oh is in the Tin Tower and Lugia is in the Whirl Islands, both at Level 45.
– There is a new feature in the game called the “Pokeathelon,” which is a mini-game feature that uses the stylus.
– The Pokemon Gyms have various traps.
– Red Gyarados appears in the Lake of Rage at Level 30.
– The Kimono Girls are part of the storyline and you meet them many times.
– Dialga, Palkia, and Giratina each learn moves they could not previously learn – Metal Burst, Hydro Pump, and Shadow Sneak (respectively).
– There are 9 mini-games. One of them could be the racing game I saw at the early premiere of the Arceus movie.
– Eusine, a character from Crystal, is in the game.
– Latios and Latias are in the games at Level 30.
– Mewtwo is in the game – Possible Kanto confirmation if it turns out to be true.
– Lugia and Ho-Oh have a “hidden ability.”