- Cross-Dressing Voices: Flowey is voiced by a woman in the comic dub.
- Descended Creator: Dohj is voiced by Dorked, the author of this AU.
- I Knew It!: The end of Part 36 confirms the popular theories that Papyrus created Flowey instead of Undyne, Mettaton is not actually corporeal with his body, and Undyne has been injecting herself with Determination.
- The Other Darrin: The first few parts of the comic dub have a different voice actor for Chara who quit not long after. The prologue, which was made after the first few parts, features Chara's current voice actor who was cast after the first one left.
- Series Hiatus:
- Quite a long one occurred from March until September in 2018, to work on the Trial video, which at one point was going to become a playable game.
- An even longer one happened from December 2018 to summer in 2019 because the Undyne fight video was being worked on.
- What Could Have Been:
- Part 36 (The Trial) was originally going to be a video, but then came the idea to make it a playable game that would be recorded and released as a video for anyone who couldn't or didn't want to play. However, a Troubled Production lead to the original decision to make it a video to shorten the hiatus, and a playable version would be made and released later.
- The Mad Dummy fight in the Core was originally going to have Frisk and Chara make them so mad that they would become corporeal with their body as a reference to the genocide run, with Chara (Who Mad Dummy can hear) saying more and more funny things every time the "Check" option was used. However, during the hiatus that happened while the Trial video was being made, the Nintendo Switch release of Undertale and the bonus fight with Mad Mew Mew resulted in her being made into a second phase of the fight, and ended with her not becoming corporeal and instead finding a better way to other than being angry. This turned out to be a good change, because not only did it give the character more depth, but also provided a way for Frisk, Flowey, and Undyne to see what Chara looks like.
Trivia / Inverted Fate