Egg Reverie Zone

The Egg Reverie Zone is the thirteenth and true final Zone in Sonic Mania. It is only accessible to Sonic the Hedgehog upon collecting all seven Chaos Emeralds. Alternatively, the player can use Level Select (with Debug Mode enabled) to access this Zone with Miles "Tails" Prower or Knuckles the Echidna. Knuckles can also access this Zone as a part of a No Save campaign by reaching the end of an "& Knuckles" playthrough with all seven Chaos Emeralds.

A void in space-time, the Egg Reverie Zone displays the final conflict between Dr. Eggman and the Phantom King for possession of the Phantom Ruby, all while Super Sonic attempts to subdue the two and take the gemstone away from the power hungry monarchs.

Overview
The Egg Reverie Zone is a purple-hued void of a barren wasteland where time and space act erratically. A single platform exists within the Zone, with several stage lights brightening up the platform.

Story
After obtaining all seven Chaos Emeralds, Sonic the Hedgehog got transported to the Egg Reverie Zone by the Phantom Ruby upon defeating Dr. Eggman's Phantom Egg inside the Titanic Monarch Zone. Within this dimension, a modified Heavy King, now known as the Phantom King, swipes the Phantom Ruby in front of Sonic. As the Phantom King mounts the Phantom Ruby on itself however, Eggman arrives in his Klepto Mobile in an attempt to take the ruby back, with the two of them taking turns holding the gem. Sonic, however, transforms into Super Sonic and fights the Phantom King and Eggman.

After defeating both villains, Sonic lands one last attack on Eggman to take back the Phantom Ruby, only for the collision to cancel out his Super State and separate him from the Chaos Emeralds, leaving the Phantom Ruby and the Chaos Emeralds to interact with one another briefly. Sonic and the Phantom Ruby are then taken through a wormhole created by the ruby while the Titanic Monarch crumbles due to the wormhole.

Gameplay
The Egg Reverie Zone is essentially an empty arena with no gimmicks or objects. Within this Zone, the player can fly by pressing the jump button while in the middle of a Spin Jump. While airborne, the player can move freely in all eight directions until the playable character touches the ground. Also, while the playable character is airborne, he is capable of performing a dashing attack by pressing the jump button. Doing so will consume five Rings.

The usual time limit is meaningless in this Zone, as the Zone timer erratically jumps between random values, indicating the fluctuating space-time in this Zone. Because Super Sonic must play this Zone, the player start out with fifty Rings instead of zero. To sustain the playable character's Ring-consuming Super State, the player must pick up the Rings that are floating aimlessly around in the Zone. Moving close to the Rings will pull them to the character, similar to the Lightning Shield. Should the player's Ring count hit zero, they will lose a life.

Bosses
Being the true final boss battle of Sonic Mania, the Egg Reverie Zone casts not one, but two bosses to fight: the Klepto Mobile and the Phantom King. In this zone, Sonic automatically uses the seven Chaos Emeralds to become Super Sonic, a Super State of which is needed for this Zone and must be sustained on Rings.

The fight is tricky at first glance, but it can be a relatively easy finale for a seasoned player. The player faces one boss at a time (starting with the Phantom King); once the player hits the boss or if enough time passes without the player making a move, it will switch to the other. In terms of attack patterns, the Phantom King uses energy spheres, which are either used to form a nearly impenetrable shield around this boss or as projectiles that can take away ten Rings from the player if they hit. The Klepto Mobile on the other hand attacks with rapid punches that can repel the player or a powerful beam.

To defeat these bosses, the player must hit each of them eight times.

Trivia

 * A "reverie" is the idea of a daydream or being lost in one's thoughts, which fits the description of the Zone.
 * This is the first Extra Zone in the Sonic series where the playable character in their Super State can run on-foot on the ground as opposed to just hovering in mid-air.
 * The idea of time and space being distorted is a concept inspired by Final Fever, the scrapped final round of the remastered version of Sonic the Hedgehog CD, in which the battle would have took place in a distorted time warp.
 * Whilst normally, this Zone can only be accessed by Sonic, it can also be accessed by Knuckles when "& Knuckles" mode is activated. The ending shows a still image of Knuckles reading a book called "Sonic Mania & Knuckles" to a group of excited animals, as Sonic and Tails look in confusion. This special ending plays a track heard nowhere else in the game; a remixed version of "New Horizon", or the title screen music from Knuckles' Chaotix.
 * This Zone is not added to the stage select available from a cleared save file, even when completed. The only way to access this Zone under normal circumstances is to complete Titanic Monarch. It can, however, be played directly by using the Level Select cheat code.
 * On the secret Level Select menu, Egg Reverie Zone is represented by an icon of the Death Egg. The icon itself is originally from the Sonic the Hedgehog 2 Level Select menu.
 * Adding a Goal Plate via Debug Mode will cause the player to instantly lose a life once it is flipped.
 * Part of the theme song that plays in this Zone has a similar melody to the chorus for "Fist Bump", the main theme for Sonic Forces.