Sonic-Mania-Decompilation

About

Sonic Mania is a 2017 platform game developed by Christian Whitehead, PagodaWest Games, and Headcannon and published by Sega for the series' 25th anniversary, reworking classic Sega Genesis Sonic stages across 13 levels as Sonic, Tails, and Knuckles. Sonic-Mania-Decompilation is a decompilation of the official Sonic Mania (Plus) client rather than a build using the original executable, so it requires the player to own an official release for its assets. It adds a built-in mod loader and API, support for building multiple official release versions (the 1.00 console release, 1.03 PC release, and 1.06 Plus update), and the option to target RSDKv5U instead of standalone RSDKv5.

How it differs from the original

Because it requires official assets, its content matches the retail release exactly, but it adds quality-of-life features absent from the official version, such as an integrated mod loader and the ability to build several past official release versions from one codebase; unlike the retail game, it explicitly does not support the Netflix Games mobile port.

Getting started

Players need to own an official copy of Sonic Mania (Plus) on Steam, the Epic Games Store, Switch, PS4, or Xbox One to supply the required assets; save data from the official PC version can be copied directly into the decompilation's folder to carry progress over.

History

The same team previously released decompilations of Sonic CD (2011) and Sonic 1/2 (2013), and spent about a year and a half building this Sonic Mania decompilation; they've stated they don't plan to decompile further titles such as Sonic Origins or Sonic 3 & Knuckles.

Known issues & limitations

• compatibility: Netflix Games version is not supported.
• Bugs that are also present in official releases will most likely not be fixed here.

What you need to run it

Features

• The project includes a built-in mod loader and API calls for modding.

How to install

1. To transfer a save from an official PC version, copy its savedata into the folder containing the project.

Additional notes

Licensing note

The project explicitly disclaims use for piracy and states it was made for educational purposes, crediting Sega, Headcannon, and Evening Star.

FAQ

What is Sonic-Mania-Decompilation?

Sonic-Mania-Decompilation is an open-source decompilation of Sonic Mania. Source code reconstructed from the original game's compiled binary, so the game can be understood, rebuilt and ported. The original game ran on Windows, Switch, PlayStation and Xbox.

Do I need the original game files to run Sonic-Mania-Decompilation?

Yes. The project does not include the original game's assets, so you need your own copy. Requires assets from the official Sonic Mania (Plus) release; project will not run without them.