- Audience-Alienating Premise: Taking the kid-friendly Sonic the Hedgehog characters and throwing them into a grimdark Crapsack World running on Black-and-Gray Morality already alienates some people by itself. And if the graphic violence and Body Horror don't turn readers off (or make them laugh), then the sheer anti-religion and particularly Islamophobic undertones will.
- Darkness-Induced Audience Apathy:
- The story had this in spades before the rewrite and was strongly criticized for it by several reviewers. The Sonic characters were even bigger jerks than their original depictions. The extremely grimdark setting didn't help, with the entire universe doomed in an over-the-top Cosmic Horror Story filled with gruesome violence, and a generous topping of Evil vs. Evil and Black-and-Gray Morality for good measure. The author rewrote it several years later partially to avoid this trope - while the setting is actually darker than before, the story itself has a somewhat more upbeat conclusion.
- This trope is also why the author discontinued the prequels Fall of the Seedrians and Battlestar Dandelion. In particular, the latter has Tsali (a genocidal mass-murdering fox android) as the protagonist against the Metarex in a blatantly Evil vs. Evil war, while Hertia and her people slowly descend into religious fanaticism, civil strife, and He Who Fights Monsters in their desperation to stay alive. And pretty much all of them are Doomed by Canon anyway.
- Narm: The original version was so narmy that the author declared it an Old Shame and decided to completely rewrite it several years after he finished it. While better than the original, even the rewritten version isn't completely free from it:
- Beelzebub would be a lot scarier as a villain if he didn't call himself Mister Fudgeicle.
- The extremely grimdark setting in general is so over the top and trying so hard to be "edgy" that it comes off as silly; this is probably why the rewrite plays most of it for Black Comedy and Narm Charm.
- Episode 73 has the utterly groan-inducing line "Oh fuckles, it's Knuckles."
- Nausea Fuel:
- Anything involving Dark Chaos Energy and what it does to unprotected human bodies, and pretty much anything involving the Shroud. Much of the gore leads into this as well.
- His Shroud infection gives Tails literal nausea fuel, as there are several scenes of him feeling too sick to get out of bed or vomiting into a toilet. His Shroud transformations are just as disgusting. Just to expand, his first transformation includes him ejaculating uncontrollably before his semen turns solid and starts slithering around his body.
- Overshadowed by Controversy: The fanfic is known more for its outright anti-religion stance, which influences the portrayal of the Angel Federation, particularly the Islamic faction.
- Tear Jerker: Tails sacrificing himself.
YMMV / Sonic X: Dark Chaos