For decades, new Sonic games — whether they were aiming to chart a new course or revisit past glories (or both) — have ranged from "conflicted" to "mostly bad". Despite this, the hedgehog has a passionate and active army of fans that still believe there's something worthwhile at the very core of the series.

Sega's latest idea is to step aside and let some of the most dedicated and talented of those fans make the game themselves and, as it turns out, it's the company's best idea in years. Sonic Mania is everything a long-suffering Sonic fan could hope for.

Produced by a small all-star team — led by Melbourne developer Christian Whitehead — who each made their name modifying and restoring old Sonic games, Mania succeeds where so many internal Sega projects have spectacularly failed. Part love letter to the '90s Sega Mega Drive franchise, part restoration project and part all new game, this title has a true appreciation for what made Sonic so beloved in the first place, and it also has something not found in any recent game from Sega's Sonic Team: restraint.

Rather than use the power of 2017 game consoles to reinvent Sonic for a new era, this is more of the Sonic you got when he was at his absolute best, albeit with the benefit of modern hardware and decades of hindsight. 

At first blush Sonic Mania feels like a direct continuation of 1994's Sonic 3 & Knuckles, with much the same style, one-button gameplay and playable cast. Unlike with Sonic 4 or any of the other attempts to take the franchise back to its roots, racing around as Sonic, Tails or Knuckles feels fantastic, with momentum that builds as you run and a feeling of inertia when you hit a loop or jump.

Spin-dashing works just like it should, with a quick tap of the down button or a standing charge, and there are no homing attacks or arbitrary new mechanics that mess with the game's flow (Sonic has a new kind of dash in place of Sonic CD's peel out or Sonic 3's guard, but it feels at home here).

Yet when you look a little deeper, even in the nostalgia-laden Green Hill Zone that begins the game, subtle differences start to appear. The beautifully colourful locations are here, but the backgrounds are much more complex and the colour palette much expanded. That timeless funky music is intact, but there's something new and energetic about it. 

Even Sonic is different, with new animations to inject more personality into his pot-bellied frame and a much smoother motion to his movement as he goes through loops and skips across water. When he crashes and rings go flying, the game keeps to its 60-frames-per second pace, a far cry from the choppy performance of the originals. Everything in the game has this familiar-yet-better quality to it. For example I love that, like many 90s games, there's no tutorials or explanations, and it's just up to you to work out what each character can do, how secrets work and how the various power-ups can interact with the environment (the water, electricity and fire shields return, but with some interesting new applications). At the same time though, the mechanics and even the stage transitions follow a consistent logic that puts it clearly in the realm of more modern games.

Mania's primary mode sees you race through 12 meticulously put-together zones, a mix of all new areas and throwbacks to past games, which are filled with secrets, robotic enemies and stage-specific gimmicks and mechanics. The throwback areas are a treat, with the first half of each being a faithful reproduction and the second half turning established features on their heads, while all the while remixes of familiar theme songs bleep and bloop along.

Yet, surprisingly, it's the new stuff that is the star of the show here, with fresh ideas and joyful twists that could never have come from Sega itself. Without spoiling anything, I'll say some of the boss battles and stage gimmicks had me grinning ear-to-ear, and the brand new zones all feel like concepts that could have been originally meant fro Sonic 2 or 3.

Special stages make a return, with the faux 3D spherical puzzles from Sonic 3 & Knuckles — accessible whenever you pass a checkpoint with more than 25 rings — awarding medals that unlock cheat modes I won't give away here. More fun are the polygonal "catch the UFO" stages, which look and feel like what we probably thought the 3D gaming future would be like in 1994. Conquering these grants Chaos Emeralds, which do what Sonic fans would expect them to do.

Aside from replaying the core game as Sonic, Tails or Knuckles to find all the secrets and unlock special features,, Mania offers a two-player split-screen race mode and an addictive time trial with online leaderboards to boot. The former is more a novelty than anything else, as it keeps the bizarre stretched aspect ratio from Sonic 2 that makes seeing where you're going very difficult.

It's no surprise that the team behind this game has a pedigree of hacks and unofficial sequels, as Mania really feels like someone broke into the old Sega Mega Drive cartridges and painstakingly updated the games with gameplay refinements, new areas and better performance.

While some old annoyances remain — like instant death traps or cumbersome sections of old maps that would have been better off left in the '90s — on the whole this is a game that will thrill long-time fans and introduce brand new ones to what Sonic is like at its very best. 

Far from the tone-deaf reinventions and cynical cash-ins of Sonic at its worst, this is a love-filled celebration that also proves there is life in the 25-year-old original concept yet.

Sonic Mania is out now for Switch (reviewed), PlayStation 4 and Xbox One, and launches on PC August 29.