Sonic UnleashedEditThe Boss Gate first appeared in Sonic Unleashed. These portal are specialized Gaia Gates created thousands of years ago to give someone access to the nearby vicinity of the local Temple of Gaia. On the PS3/Xbox360 version the Boss Gate is a circular pad with a red light emerging from it and displays the symbol typically associated with Dark Gaia, while on the PS2/Wii version they are doors with star patterns found inside the Gaia Gate. They are named Boss Gates by Professor Pickle due to the strong opponents that guard the Temples of Gaia.
On the PS3/Xbox360 version, Sonic has to obtain the Boss Gate's Gaia Key, by collecting its two halves from each continent in order to activate the Boss Gate. On the PS2/Wii version Sonic instead has to obtain the Planet Tablet in order to open the Boss Gate, which is done by also collecting its two halves. The halves from each of these keys are collected by completing the continent's night - and daytime Stages.
Sonic GenerationsEditIn Sonic Generations all of the Boss Gates are located in the White Space. The outer layout of the Boss Gates is a floating portal made of gears and locks. Just like the other places found in the White World, the Boss Gate leads to a different point in Sonic's history, but instead of just a location, it brings Sonic into the middle of the battles with some of his biggest opponents (The Death Egg Robot, Perfect Chaos and the Egg Dragoon). In order to open a Boss Gate, the Sonics have to collect three Boss Gate Keys for each Boss Gate, which is scattered throughout the White Space. After clearing a Boss Gate, a Chaos Emerald is restored from its colorless state and passed on to one of the Sonics.
In the 3DS version, the boss gates have both a rival and a big opponent (Metal Sonic and Big Arm in the first one, Shadow and the Biolizard in the second one, and Silver and the Egg Emperor in the third one). In order to open the gates, the Sonics must restore all of the zones of each era. Once they reach a boss gate, they must defeat the rival in a race before they can battle the big opponent.
Unlike the other areas in the White World, which leads directly to a point in Sonic's history, the Boss Gate's entrance first leads to the interior of the gate, which features a rather large black and white hallway, decorated with white chandeliers and (at least in the Death Egg Robot's Boss Gate's case) a wall with transparent glass cutting through the middle of the room which. Each end of the hallway has a stone door that leads respectively to the boss and back to the White World.
- It may be that the Boss Gates in Sonic Generations were created by Dr. Eggman as one of the traps he had set up for Sonic; their layout suggest the places they lead to was not torn away from their place in time, as the other areas, the gates is mainly constructed out of gears, which is associated with the Time Eater and finally, it appeared that Eggman had expected Sonic would pass through the Boss Gate when he is about to fight the Egg Dragoon.