The story follows Sonic, Tails and Knuckles as they venture to defeat Doctor Eggman and his robotic henchmen, the Hard-Boiled Heavies.

Art, level design, audio, and additional programming were provided by independent studios PagodaWest Games and Headcannon.

Its presentation, level design, music, and faithfulness to the early Sonic games were praised, but its lack of originality was criticized.

At the end of each act, the player takes part in a boss battle against Doctor Eggman, also known as Dr. Robotnik, or one of his robots, including the Hard-Boiled Heavies, elite henchmen based on the EggRobo enemies from Sonic 3 & Knuckles.

Television monitors containing rings, elemental shields, or power-ups such as invincibility and faster running speed are scattered throughout each level.

[13] Giant rings hidden in each act, a feature of the original games, lead to pseudo-3D special stages similar to those in Sonic CD,[8][13][14] where players can attempt to collect a Chaos Emerald.

In special stages, players dodge obstacles and collect colored spheres to increase their speed, allowing them to pursue a UFO carrying a Chaos Emerald; collecting all seven Chaos Emeralds allows players to use their character's super transformation and unlocks the game's true ending.

The EggRobos excavate the source of the signal, a magical gemstone called the Phantom Ruby, just as Sonic and Tails arrive.

The Heavy King grabbed the Phantom Ruby and uses its power to take Sonic and his four friends back to the beginning of their adventure in the game.

However, this time, Sonic and his allies use the Chaos Emeralds to activate their super forms to escape while Eggman is sent into a portal created by the Phantom Ruby.

[13][17] After developing the game for a few months, Whitehead presented a prototype, which he called Sonic Discovery, to series producer Takashi Iizuka.

[13] Iizuka was receptive, and suggested that it should include old levels from the early Sonic games it was inspired by, "remixed" in a way that felt new.

[20][21] The team also included programmer Simon "Stealth" Thomley of the independent studio Headcannon, who assisted Whitehead with those projects and on various Sonic fangames and ROM hacks,[22][23] as well as level designer Jared Kasl and art director Tom Fry of PagodaWest Games, who had previously independently collaborated on an unofficial high-definition remaster of Sonic 2.

[26] According to Thomley, the team typically decided what elements to include in the returning stages prior to designing them, but sometimes came up with new ideas or changed them based on how the development progressed.

[28] The desert-themed Mirage Saloon Zone was inspired by an unfinished level from Sonic 2 and the Monument Valley region of the United States.

[35] Lopes initially wanted his score to resemble the Sonic CD soundtrack, trying to imagine what a sequel to it might have sounded like.

[43][44] To promote the collector's edition, Sega released a retro-styled infomercial featuring former series art director Kazuyuki Hoshino and social media manager Aaron Webber, based on an American television commercial for Sonic The Hedgehog 2.

[49] The three bonus tracks were also released as singles under video-game record label GameChops on digital music distribution platforms.

[48] In an interview with Famitsu, Iizuka explained that Sonic Mania was not intended to have a physical release; Sega staff requested one, but a retail version would have presented a challenge for the production schedule.

[76][87] At launch, Sonic Mania was the bestselling Switch game, outselling Minecraft and Overcooked: Special Edition.

[91] GameSpot called the animations and detail superior to the original games, writing that they added an extra layer of personality.

[74] Easy Allies wrote that Mania emulated the original games "exceptionally", and that "running, jumping, and spin dashing all work exactly as well as you would hope".

[93] Nintendo World Report wrote that it avoided the physics problems from Sonic the Hedgehog 4 and recaptured the spirit of the 16-bit games.

[78] Hardcore Gamer wrote that the remixed versions of older stages felt fresh while staying true to the originals.

[80] VideoGamer.com wrote that the game relied too much on nostalgia, with minimal innovation and too few original stages, but was a good proof of concept that the development team could expand upon.

[78] The Windows version was subject to review bombing due to its implementation of the digital rights management (DRM) software Denuvo, which some thought to be the real reason behind the two-week delay.

[78] Waypoint compared it favorably to Donkey Kong Country Returns, describing it as a game that knew "what was fun" about its predecessors.

[101] Nintendo Life felt that Mania represented "a true return to form" and was a contender for the best game in the series.

DualShockers' Tomas Franzese praised the "Encore" mode for feeling fresh, as well as the movement options introduced with Mighty and Ray.

[103] IGN Spain did not recommend the update for those that own the original game, but commended the physical release and the added value for new players and hardcore fans.