How to Get the Metal Sonic in Sonic Adventure

Start the game and select "new game" or "continue" from the main menu. This choice depends on whether you have a saved game already or are starting a new game. Begin the first adventure and play until you rescue "Tails" and walk with him to the train station Hotel. You will receive a "Chaos Emerald" and need to move to the other side of the hotel to the street facing the ocean. The train station will now be visible. Enter it to travel to the second adventure world, the "Mystic Ruins." Collect as many emblems as you can, as these will be very important later.

Play through the second level and destroy the boss, "Chaos 6." In a cut scene following the battle, "Knuckles" will appear and the villian "Eggman" will get upset you beat "Chaos 6" and run away. Sonic chases after him and falls into the "Mystic Ruin Rain Forest." As you visit the "Egg Carrier" located on the edge of the forest, you will see two robotic Sonics levitating in liquid containers. The black one with attached wheels is the "Metal Sonic."

Collect the 130 emblems scattered throughout the game then restart the game and start the "Trial Mode" from the options menu. You will now be able to play as "Metal Sonic." This character is not playable in regular mode.