Sonic XG

Sonic XG started out as early as 2002 by Euan "Sir Euan" Gallacher. The original plot involved Eggman gaining the power to "dramatically change history", with Sonic having to gather every Time Stone in different time periods.

After the demo featuring Peak Panic, Desert Dash and Palm Paradiso, Joseph "Nitemare" Waters, got interested in the project and started talking with Euan around the time XG got merged with with MystHedgehog's Sonic Eternal Rings, becoming Sonic Forever. A website was of which was available in 2005. In early 2005, the public engine test build for Sonic Forever was available for testing purposes. The engine was lost on the internet but was later found again in 2013. The project failed because of the two-man partnership not working out, alongside the sudden disappearance of MystHedgehog. Euan, now having Joseph by his side, went back to the name Sonic XG because of the lack of any confirmation from Myst in terms of zones and assets usage. The new Sonic XG was intended on having the game take place immediately after the events of Sonic & Knuckles. Back in around 2007, ten zones were planned as shown on the website, whilst two of them were kept in secrecy.

Shortly after the release of the Final Fall Zone demo in August of 2007, Euan and Joseph started talking with Christian "The Taxman" Whitehead about XG and Retro Sonic, ultimately ending up sharing similar interests on both sides. With the three of them combined, the project ended up becoming Retro-Sonic XG, which would've ported the XG levels over to the Retro-Sonic engine, while including some of Retro Sonic's own zones like Robotic Resort Zone, a revamped version of Egg Garden Zone (which is still present in XG's current incarnation.). Both Joseph and Euan went their separate ways in real life shortly after this decision was made.

Approximately two years after the Labor Day demo release of Sonic Nexus, with the Retro-Sonic Engine, now having its commercial name in the Retro Engine, it was discovered that it would be difficult to get both Retro-Sonic XG and Sonic Nexus done as separate games. In order to consolidate time and resources, it was decided to merge the two projects together, ultimately becoming Retro Sonic Nexus, which got announced the following year.[1] The game was mainly worked on by the Nexus team; Brad "Slingerland" Flick, "The Taxman" and "Hunter Bridges". With contributions from colleagues involved with the other projects. Retro Sonic Nexus was then ultimately shelved when the development team announced the discontinuation of the fan game in August of 2011 in favour of the Retro Engine version of Sonic CD, which released that December.

In 2012, Joseph Waters discovered the discontinuation of Retro Sonic Nexus and took it upon himself to wrap up what was started nearly a decade ago and decided to make Sonic XG again as a standalone title using some of the assets "The Taxman" still had from Retro-Sonic XG. It intended to be released under Sonic XG Lite, which would've only contained 6 zones. However, the amount of zones currently present is unkown. On Joseph's YouTube page, there are currently four previews of the game, showcasing some of the zones that will be present in the final game (although Golden Gate, which is still featured in those previews, has been removed from the game and has since been replaced by Cyber City, a Genocide City-inspired zone.).

On September 23rd, 2021, A new announcement teaser was uploaded to Twitter under a brand new account, showcasing a new iteration of the project running a custom framework for Clickteam Fusion 2.5. In 2024, this new iteration was scrapped in favor of a new direction. This version is being developed by fan game circle Ultra Ring in collaboration with Euan and is being built using the Harmony Framework for Game Maker Studio 2.