The team at Paramount has decided to write our own unique story that hasn't been used before in the franchise. This helps to not impede on our artistic freedom. Fans may anticipate a traditional origin story where Sonic comes from his own world but Sonic was not transported into the human world, he was always a part of the human world
the game will use the same character model for Sonic that has been shown from the movie leaks.
frame-rate will be capped at a solid 30fps with only minor drops during levels with water. Schmortega claims that Sega is no longer targeting 60fps as gamers only are interested in eye candy according to their internal surveys.
https://www.sonichq.net/article/Sonic-movie-tie-in-to-upcoming-game-plot-details