Metal Sonic (Sonic Mania)

Metal Sonic (メタルソニック) is the second boss of Stardust Speedway Zone and the twelfth overall boss of Sonic Mania. He is fought with Sonic, Tails or Knuckles at the end of Stardust Speedway Act 2, after the player destroys a Metal Sonic Projector.

Boss guide
The battle begins after the player destroys a Metal Sonic Projector. The music stops and Animals rush on screen with nothing happening for a few seconds until Metal Sonic suddenly appears and begins the fight by initiating a race.

In this first part of the fight, Metal Sonic cannot be damaged. Instead, the player must make it to the arena while dodging Metal Sonic, who will be flying around trying to Spin Dash the player, fly into them using his Ring Spark Field, or use the V. Maximum Overdrive Attack to attack the player from behind.

When the player reaches the arena, Metal Sonic will interface with a gigantic Eggman-shaped generator to control it. The generator's "mouth" will then open as a Silver Sonic emerges from it. This Silver Sonic has three attack patterns: it will either attempt to attack the player with a Spin Dash, swipe at the player using their extendable claw arms, or dash forward using their jet boots until they hit the edge of the screen. While the Silver Sonic can be disposed off with one hit like a normal Badnik, another one will spawn immediately after its destruction. Metal Sonic will also occasionally fire balls of electricity towards the player in an attempt to damage them. When the Silver Sonics rev up their Spin Dash, the player must perform a Spin Attack on them to make them bounce around the room and hit Metal Sonic.

Once four hits have been dealt to Metal Sonic, the generator will explode. Metal Sonic will also reject from the generator and the chase will resume. Along the way, Metal Sonic will attack like he did previously until the player reaches the top of Stardust Speedway where an Eggman statue awaits.

Once the player reaches the top, spiked blocks will drop in from above, creating a spike wall. Metal Sonic will then fly in and do his iconic taunt before beginning to hover on the ground and fly to the right as the spike wall starts to close in. From there, the player must outrun the spike wall and hit Metal Sonic after he attacks, which is when he is vulnerable. During this phase, Metal Sonic will utilize a bouncing Spin Dash attack or the V. Maximum Overdrive Attack if the player is not too far away from him but still ahead. If Metal Sonic is off-screen, he will activate his Ring Spark Field and fly ahead to launch multiple sparks at the player from the air (although he is still prone to doing this move if the player is behind him when he is about to pull off a attack).

Once Metal Sonic has been hit eight more times, he is finally destroyed and the Capsule will float down from the sky, allowing the player to complete the Zone.

Trivia

 * The dock that Metal Sonic inserts himself into during the first phase is near identical to the one seen in his boss battle at World Entrance Level 1 in Knuckles' Chaotix.
 * The race sections in this boss battle are similar to original race against Metal Sonic.
 * The sound effects used for Metal Sonic are based on those heard in Sonic the Hedgehog CD, the game in which he debuted.
 * The sound effects used for the Silver Sonic are based on those heard in Sonic the Hedgehog 2 (8-bit), the game in which it debuted.
 * The projectile attack used by Metal Sonic during the second phase is very similar to one used by Mecha Sonic whilst in its Super State in Sonic & Knuckles.
 * Dr. Eggman can be seen locating Metal Sonic in Press Garden Zone, the Zone before the current one, foreshadowing this boss battle.
 * During the first phase of the fight, two damaged Metal Sonics can be seen housed in green tubes at both ends of the screen. The significance of this is unknown.
 * If the player collides with a Silver Sonic with enough speed (most easily achieved when using a super transformation), it will cause it to bounce off the top of the screen and a new Silver Sonic will be produced. However, the original Silver Sonic will eventually fall back down to the ground given enough time, making it possible to have multiple Silver Sonics on screen at the same time.
 * The generator seen in the first phase of the fight is very similar to the Robot Generator seen in Sonic the Hedgehog: The Movie.