Unknown

Unknown is the eighth stage in the game Sonic Rush, and the final stage of both Sonic and Blaze's stories. It is the penultimate boss battle of the game, followed by Exception.

The only event that occurs here is the final battle against Doctor Eggman or Eggman Nega in a giant mecha. At first, it will remain in the background and attempt to pound Sonic or Blaze with its fists, which release shockwaves, or fire a laser which leaves behind a brief fire trail. Eventually, it will move to the right side of the ship and attack similarly there. After several shockwaves, the fist stops moving and the player can hit it, immobilizing it and allowing them to run up and hit the cockpit. An on-screen prompt lets the player know when to duck to avoid being shaken off at certain points.

After four hits, the mech changes its pattern and includes a new move. It can release a probe that hovers over the player and unleashes electrical bolts that must be stayed between until it disappears. Once it disappears, the mech will move to the side again to allow the player to attack it.

On its final bar of health, Eggman will launch a kamikaze attack and try to destroy the battleship by ramming it. There's nothing the player can do until the third hit, where it will remain in place. The player can then launch the final hit and destroy the robot.