Lair of the Time Eater

The Lair of the Time Eater is a location that appears in the console/PC version of Sonic Generations. It is a hidden location within in the White Space where the player can repair special temporal gears and unlock the entrance to the Time Eater's dimension.

Description
The Lair of the Time Eater is composed of countless gears and clockwork parts floating in midair and with black brick walls and floors enclosing the general area. In the foreground are seven golden gears, each one with smaller platforms, and in the far end of the Lair is the portal to the Time Eater's dimension where the final boss of the game is.

In gameplay, the Lair of the Time Eater can first be visited after clearing the Egg Dragoon boss battle. When first arriving in the lair, the seven golden gears are fractured and the portal to the Time Eater's dimension is closed. The player's objective is as such to repair the gears using the seven Chaos Emeralds. While it is never said how the Chaos Emeralds are related to those gears, it appears that the Emeralds' power are the only suitable to repair them.

Every gear in the lair can be activated by one Emerald by simply approaching them. An Emerald will then automatically float into the center of the gear which will make it permanently reassemble itself and start to turn (the gears can be restored in any order). The player can afterwards use the rising platforms on the gears to reach the next one. When all the Chaos Emeralds have been inserted, the big portal to the Time Eater's dimension will rotate and its torches will be lit one by one. When all twelve flames are ignited, the portal will open and the Chaos Emeralds will return to Sonic, allowing the player to reach the final boss.