At the end of Sonic Adventure, Station Square is left in ruins after the fighting finishes. This is treated nonchalantly by the series and is never discussed. Fallen Angel attempts to deal with this issue.
After Sonic runs after Doctor Eggman, with Tails and Knuckles soon running off as well, Amy Rose is left abandoned in the wreckage. After no one comes to help her, it's up to Amy to find her own way to safety. After Amy is rescued, she lives with other Station Square survivors and evacuees in a shelter. While there Amy spots a quiet human girl that catches her attention. The two soon spark a friendship, but there's more to Amy's shy new friend than meets the eye.
Fallen Angel provides examples of:
- Adaptational Jerkass: While not particularly uncommon for 8-year olds, Tails teasing Amy is crueler than his norm. He and Amy are on negative terms which differs greatly from canon. It could be because the fanfic (being from 2002) dates back to when Tails' characterization was still sparse.
- Adaptation Relationship Overhaul:
- In canon, Amy and Tails are friendly towards each other, but this fic depicts an animosity between the two.
- Future titles depict Knuckles and Amy on positive enough terms. In Fallen Angel, Amy doesn't even know Knuckles' name. This is because the two don't interact in pre-Adventure main games.
- Age Lift: Amy is two years older than in canon, being fourteen instead of twelve.
- Dark Fic: Fallen Angel adds a dose of reality to the ending of Adventure, as well as the damage caused by Eggman's previous escapades.
- Deconstruction Fic: The fic deconstructs Sonic Adventure's ending. Station Square is in ruins and Amy is left stuck on a random plot of land surrounded by water. Amy doesn't have any special abilities like Tails or Knuckles, so all she can do is wait for help until she decides to try and go to safety herself (which takes effort).
- Despair Event Horizon: Partway through, Amy comes to the realization that she has no friends and that she's been deserted by both Sonic and Tails. She becomes so miserable that she wishes she had died in the damage. Even after being rescued, Amy is still depressed over her life until she meets a human girl her age.
- Friendless Background: Amy was one of the youngest in her orphanage and was ignored by everyone. Even current time, she doesn't have any actual friends. She has acquaintances, but doesn't have anyone who genuinely is a friend.
- Full-Name Basis: Amy refers to Tails by his real name "Miles" and uses a Full-Name Ultimatum on him.
- Harmful to Minors: At age 8, Sarah saw her city ravaged and her first love die in front of her.
- Minor Living Alone: Like in canon, Amy lives in her own apartment.
- Parental Abandonment: Amy grew up in an orphanage. Her parents mysteriously vanished when she was younger.
- Puppy Love: Sarah had a boyfriend at age eight, but he moved with his parents and they lost contact. Or so she says. In reality, Sarah is from Starlight City. Jason died alongside her classmates when Robotnik attacked.
- Rich Bitch: Subverted with Sarah. After Sarah runs off, Amy tries to think of her as a spoiled snob in order to stop caring about her. As it turns out Sarah has different reasons for avoiding Amy.
- The Rival: Amy mentions that Tails is her rival for Sonic's attention.
- Token Minority: Discussed. Amy, being the only hedgehog in (a presumably mainly human) town, always felt like the odd one out.
- Token Minority Couple: According to the timeline in the director's cut, Amy was drawn to Sonic because she had little experience with other hedgehogs. She's an orphan who was the only hedgehog in Never Lake, so hedgehogs are a novelty to her.
- Trauma Button: Sarah freaks out when Amy asks her where she's from.
- What Beautiful Eyes!: Amy's human friend Sarah has strikingly pure blue eyes. Unfortunately, she also has red marks in her eyes that cause her to be bullied.