Those who have completed Sonic the Hedgehog 2 are likely familiar with its Final Boss, the Death Egg Robot, notorious for being hard even by final boss standards. Eggman shows that he means business in Mania by siccing that same robot, albeit with a few modernizing upgrades and a drop in difficulty, at the end of the first Zone in the game!
Dont want to use debug? Then get all seven Chaos Emeralds and beat the Phantom Egg using the & Knuckles mode, and Knuckles will be able to still fight the true final boss.
The natural final boss of the game. Eggman, instead of using a massive machine or complex Eggmobile addon, created a personal power suit to fight you in; the Phantom Egg. Powering it with the Phantom Ruby and tethering it to the four corners of the room for stability, he proceeds to provide the most intense fight in the game, using the Ruby's spacial distortion powers to create energy fists that teleport Sonic, Tails, and Knuckles to different rooms, where it's revealed he also allowed the Hard-Boiled Heavies one last shot with the ruby to turn them into the Phantom Heavies.
Sonic Mania is the highest-rated Sonic game on Metacritic since the original Sonic Adventure 2's 89 score, with the PS4 version scoring an 86, Xbox One a 82, and the Switch version a 92.
One of the extras you can unlock is a new Blue Sphere mode that incorporates additional spheres in the form of greennote double-hit spheres that require you to run over them once to turn them into blues, then again to claim them, which cannot be turned into rings until they've been turned blue and pinknote teleportation spheres that move you to another such sphere somewhere else on the grid spheres. These originate from an idea that Simon Thomley (aka "Stealth") originally concocted for a never-produced remastered version of Sonic 3 & Knuckles that, among other things, would feature an updated Blue Sphere minigame. Mania finally gave him the chance to realize this.
The debug mode is unlocked this time around instead of requiring a cheat code, and is otherwise true to the originals, allowing the player to abuse the game in all sorts of ways. While placing monitors, pressing a certain button will flip through the different monitors, including the "S" monitor which instantly gives 50 rings and activates Super Mode regardless of emeralds obtained.
"I had fun playing Sonic Mania there I said it". And who said that? Arin Hanson, who has been very vocal about his dislike of the previous Sonic games they've played on the show. During the Game Grumps first episode of Sonic Mania, co-host Dan Avidan notes that Arin is really enjoying himself. Quote from here.
Unlike Sonic 3 & Knuckles, this game's elemental shields can affect the environment. The Fire Shield can burn through spike bars in Green Hill Zone and ignite the oil in Oil Ocean Zone, while Lightning allows you to be pulled up by electric currents in Flying Battery Zone and Titanic Monarch Zone.
The transition from Stardust Speedway Zone Act 1 to Act 2. Your character destroys the roboticizer resulting in the "Good Future obtained" chime, passes by a Future post, then hits a booster to time-travel to Act 2 in exactly the same way time-travel is done in Sonic CD.
The Mania Plus update adds new transitions to Press Garden, Stardust Speedway, Hydrocity, Oil Ocean, Lava Reef, and Metallic Madness, and they're all as impressive as the others.
At the end of Flying Battery, Sonic grabs onto a hang glider from the 8-bit Sonic the Hedgehog 2 all the way down to Press Garden.
At the end of Oil Ocean, the submarine shoots Sonic all the way to Lava Reef, landing him in a Dummied Out section of the original Lava Reef Zone in Sonic 3 & Knuckles.
The Heavy Rider's boss arena shoots up into the sky, and by the time the battle ends, you can see the whole of the roboticized Little Planet.
Finally, after clearing Metallic Madness, we get a short cutscene of the Titanic Monarch in the background, looking foreboding and frightening as hell.
The update also revamps the Stardust Speedway Act 2 boss with the Phantom Ruby transforming Metal Sonic into his final boss form from Knuckles Chaotix!
The fact that, despite being digital-only, the game has sold over 1 million copies, which is impressive for a digital-only game.
Gotta give kudos to Heavy Magician; from what we see of Encore, she was the only Hard-Boiled Heavy to survive.
With the release of Encore mode, She reveals that not only did she survive, but she gathered the damaged Heavies together, and set a trap within Eggman's trap to get the Ruby back to Heavy King, who was himself still clinging to life long enough to turn back time itself to when the Ruby was first unearthed.