
Sonic Robo Blast 2 is a 3D Sonic game that uses a modified version of the Doom Legacy engine and has been in development since 1998.Retro Sonic Nexus was ultimately cancelled in 2011, splitting up the three projects, while Christian went on to work with Sega to make the 2011 remaster of Sonic CD.

It is the first game to use the Retro Engine (the engine used for the 2011 remaster of Sonic CD), and later merged with two other Sonic fangames, Sonic Nexus and Sonic XG, to form Retro Sonic Nexus, a collaboration project made by Christian Whitehead.

Sonic Utopia is an open-world, 3D Sonic game, currently in development.This game gained notability for receiving a positive response from Sega. Green Hill Paradise Act 2 is a 3D Sonic game built by Daniel "SuperSonic68" Coyle and other collaborators with the 3D Sonic Games Development Kit.The following are all original games based on the Sonic series.

Sega is permissive of most fangames, as long as they are not for profit. Due to the popularity of the franchise, some of these products have received media attention. These products include video games, video game mods, ROM hacks, comics, and animations. Unlicensed developers and fans have created unofficial Sonic media, especially video games, relating to the Sonic the Hedgehog franchise. You can help by adding missing items with reliable sources. This is a dynamic list and may never be able to satisfy particular standards for completeness.
