The White Space is the main setting of Sonic Generations. It is a realm between dimensions that holds the universe together and the area that both Classic Sonic and Modern Sonic travel through over the course of the story.
The White Space is presented as a completely white void-like limbo, where time does not exist. It is the area where places in space are sent to after they have been damaged by the Time Eater.
The two Sonics can access all of the levels in the game here, as this is the hub-world of the game, and they can also find the various bonus features that can be unlocked through various requirements. This area also contains the Collection Room, the Skill Shop, and the Information Pod.
Video game eras
White Space is divided into five areas. Three of these areas are dedicated to the eras of Sonic's life by video game era. Before Classic Era is the shop and bonus features and after the Modern Era is where the player can fight Time Eater at the Center of Time once they have collected all the Chaos Emeralds.
The Treasure chest on the 3DS version's collection room is the same treasure chest that appeared at the end of the levels in Sonic Rush Adventure.
There are signs in the Speed Highway Hub showing places based on different characters names.
Completing the levels and all the missions brings the colors back to White Space.
The Nintendo 3DS version of White Space is not an explorable hub world. Instead, it functions more like a simple level select, with the level's icon displayed on the top screen, and the Acts and other info displayed on the bottom screen. Neither Sonic is seen on the top screen. Due to this, the missions are not located in the White Space—a separate menu on the title screen accommodates this function.
According to Modern Eggman, there is no time in White Space.
The Dreamcast Era and the Modern Era have different names for the 3DS version, the "Adventure Era" and "DS Era".