Egg Pistons mk.II

The Egg Pistons mk.II is an object that appears in Sonic Mania. It is a weaponized piston room in Metallic Madness Zone created by Dr. Eggman, and an improved version of the final trap Eggman set for Sonic back on South Island.

Appearance
The Egg Pistons mk.II machine consist of an entirely mechanized room in Metallic Madness Zone, which has only two entrances into it. The room's ceiling and floor are equipped with gray and hollow metallic pistons big enough for Dr. Eggman to reside within. These pistons are so closely packed that together they can fill out their entire room. Also, on the right side of the Egg Pistons mk.II's room is a red bulb-like generator for firing energy spheres.

Features and abilities
The entire room that makes up the Egg Pistons mk.II machine is one massive trap. Once someone enters it, the exits will close off, preventing any and all escapes. The room's pistons can then protrude from the surfaces they are embedded in for the purpose of squishing any unfortunate victims caught below them. Adding to the danger of this room, its red bulb-like generator can manifest energy spheres that can home in on any victim that manages to stay alive.

History
Built into Metallic Madness Zone, the Egg Pistons mk.II machine was used by Dr. Eggman to combat Sonic, Tails and Knuckles when he managed to trap the trio in its room while they passed through the Zone. While the heroes fought back against the Egg Pistons, the extensive damage they dealt to it eventually caused the machine to go haywire, making it much more dangerous. Regardless, Sonic and co. survived long enough to make the Egg Pistons mk.II machine blow up with Eggman inside it and escape to freedom.

Battle
The Egg Pistons mk.II is the mini-boss of Metallic Madness Zone and the twenty-first overall boss of Sonic Mania. It is fought with Sonic, Tails or Knuckles at the end of Metallic Madness Zone Act 1.

Boss guide
Like the original boss in Final Zone, Dr. Eggman uses the Egg Pistons mk.II as crushers. During the initial phase of the battle, Eggman will attack the player with two pistons at time, which will emerge from either the ceiling or floor; Eggman himself will be hiding inside one of these pistons. To inflict damage on this boss, the player must attack the piston Eggman is residing it. In addition, after each piston's launch, the red bulb on the right will create four damage-inducing energy orbs that will fall down slowly while homing in on the playable characters. As long as the player is quick and does not leave themselves cornered, these orbs are easily dodged with a jump or Spin Dash.

After landing four hits on the pistons, the Egg Pistons mk.II machine starts to blow up and go haywire, causing the screen to flash red and destroy the bulb producing the energy orbs. After that, the pistons begin deploying individually in quick succession. Before a piston fires itself though, it indicates this by shaking. The order in which they fire is random. However, the player must still attack Eggman, who will now appear in every fourth piston, to damage this boss.

Landing another four hits destroys the Egg Pistons mk.II machine completely and ends the fight. The player can then proceed to the Goal Plate and finish the Act.

Trivia

 * The Egg Pistons mk.II is based on the final boss of the original Sonic the Hedgehog, the main physical difference is that the Egg Pistons mk.II have five pistons while the original only has four.