An earlier version of "Soul Clash" by KKV2006 used in ItsYaBoi_Joseph's D-Side Sonic.exe mod has drawn the approval by a lot of the dev team, with one of the artists, EllisBros, saying that it’s the kind of content they live for and the creator of the mod, DastardlyDeacon, saying that the team listened to the song in a development call and everyone in there loved the song.
DastardlyDeacon also voiced his approval of a fan-made lyrical cover of "Cycles D-Sides", seeing it as really impressive to tackle a song as long as that and also enjoying the central theme of each character being forgotten and never getting anything past the Genesisnote Granted, Alex Kidd did eventually get an official modern game sometime after that, but still.... He also liked the subtle Take That! to the 12-year-olds in the community who most likely never knew about said characters before their appearance in this mod.
Jack Gore, creator of Hog/Scorched, liked Hare & Labyrinth (Fanmade D-Sides versions of Hog & Scorched) so much that he even approved them as the official D-Sides variants of Hog & Scorched.
Ever since Mighty.ZIP introduced the concept of speaking poetically in the middle of a song, there were a few mods featuring characters creating their own verses with the idea. The most well known imitator of this concept would be Oswald from Wednesday's Infidelity, who himself was featured in a D-Side remix. Even Mighty.ZIP's normal universe counterpart, Sonic.exe, received a rhyming verse in the Encore version of "You Can't Run".
The Other Darrin: In "God Feast", Sonic.exe uses a new chromatic scale made by DastardlyDeacon, as opposed to his chromatic scale from Vs Sonic.exe by MarStarBro.
Promoted Fanboy: kiwiquest made a fan remix for "Thorns" before being brought onto the mod to compose official remixes for "Endless", "Milk", and "Cycles", and officially collaborated for D-Side variants of songs from their own mod, VS OURPLE GUY.
The original idea for D-Sides Senpai was a regular guy who worked as a comedian, with Spirit being Adapted Out from his story; this was scrapped in favour of Sensei.
Originally, a .EXE version of Knuckles was going to take Sonic.EXE's place. However, it was later changed to Mighty.ZIP because the creator felt that using a more obscure Sonic character gave them more wiggle room to flip everything on its head.
Back when D-Side Vs. Sonic.exe songs first came to mind and Knuckles was still planned to take the place of Sonic, a concept for a Knuckles version of Revie_03's EXE]] was drawn up, but scrapped following the controversy with Revie_03, FalseCow_ and KubiCorg.
The crossover was initially going to include the entirety of the 3.0 update, but following Vs. Sonic.exe’s cancellation, it was instead changed to focus on the 2.0 update, Slaybells, Final Escape and Fatality.
Speaking of the 3.0 crossover, a new EXE; Cosmo.EXT, was also planned to the mod, but was scrapped due to the crossover's cancellation as well as the RoleEndingMisdemeanors with RightBurst_Ultra and FalseCow_.
Initially, there were plans to include a D-Sides variation of Needlemouse based on Max the Rabbit named Usaguro, but she would end up being scrapped by request of ShutUpJoJo. Luther was also planned for the mod too, with his design becoming based around Sonic, but the idea never got much off the ground.
There were plans to include a D-Sides version of "Personel" against just a completely normal Sonic, but the plans were scrapped following Role Ending Misdemeanors with both the composers of the song (Adam McHummus and JesterFrog). Fortunately, the drama regarding Adam was quickly resolved, as the latter took steps to cut off all association with Jester as well as Creepercrunch and RoxyBoo.
"Brimstone" was initially planned for the mod, but was scrapped following a controversy involving the song’s composer (TheInnuendo).
A D-Sides version of "Pasta Night" would end up getting drastically changed to avoid association with TheInnuendo, with a rename to "Double-Down" and moving away from the crossover aspect with Lullaby entirely.
A crossover with Mistful Crimson Morning featuring Red Mist Squidward and Dumped Spongebob had been planned, but it ended up being scrapped following the controversy with the mod's owner (mainly BetaSheep), and there are currently no plans to bring back the crossover following the mod being revived.
A D-Sides remix of Think was intended for the mod, but was scrapped following controversy surrounding Alex Kister.
Word of Gay: Per word of DastardlyDeacon, Boyfriend is bisexual like his canon counterpart, Girlfriend is pansexual, and Daddy Dearest is a trans man. Mighty.ZIP is attracted to men, though his orientation is otherwise unspecified.