Board Thread:General Discussion/@comment-25826354-20170316232415/@comment-679780-20170317015843

Here are some theories/fan-wishes of mine:
 * Dr. Eggman repaired the Death Egg mk.II and used it to cause the events in Sonic Forces. The story may involve collecting the Time Stones. The Chaos Emeralds maybe an optional collectible for Super Sonic but unneccisary to the game (unless they're all needed to unlock final story or true ending). The game may end with Sonic preventing Sonic 4 from ever happening, or very least the ending of Sonic CD where Dr. Eggman takes one of the Time Stones.
 * That isn't Classic Sonic from Sonic Generations in this game since Dr. Eggman prevented the classic era of Sonic games from happening. However due to cause and effect, the classic era was replaced with Sonic Mania and the Sonic from that game will eventually travel to his future where Sonic Forces take place.
 * A third gameplay is confirmed. I believe it is a Sonic Adventure like gameplay reserved for non-Sonic playable characters such as Tails, Knuckles and Amy. There will be no "Dreamcast Sonic".

These are just theories though and doubt Sonic Team would put such attention to detail for the story.