Deltarune's Susie refers to the act of turning Noelle into a robot as being "roboticized", a term that was popularized by the Saturday morning Sonic the Hedgehog cartoon and Archie's Sonic comics.
Shadow the Hedgehog has achieved the unique feat of warping between three different comics back to back. In-universe, he warps from Moebius to the world of Sonic X, over to the Sol Dimension, then back to Mobius. This goes from StH, to Sonic X, finally ending in Sonic Universe.
Multiple Archie Sonic comics feature plug & play technology where the reader can grab their Sega Genesis controller and guide Sonic through a segment of the story. One of these instances is a scripted quick time event where Sonic loses at the fault of the reader/player.
The Society for Observing and Neutralizing Interdimensional Creatures and Xenomorphs is an organization founded by several individuals who's lives Sonic had ruined through largely indirect means. When told of S.O.N.I.C.X.'s name, Sonic the Hedgehog takes great amusement in it.
@NibrocRock I get this energy for some reason and that just sounds hilariously amazing
Amy Rose seems to be the only character in the main Sonic the Hedgehog cast who can handle a casual punch from Knuckles.
Scott Pilgrim's high school band "Sonic & Knuckles" is a very subtle reference to the 1994 Sega Genesis game Sonic & Knuckles.
Sonic the Hedgehog does not know what hedgehogs look like.
Whisper the Wolf's design began with an in-game custom character in Sonic Forces. From there, she would gradually evolve into her final look.
Tails is very discontent with the fact that Eggman has settled on making Tails Doll rather than a Metal Tails. Moreover, this suggests that he finds Metal Sonic and Knuckles to be particularly cool.
When robots or lackeys fail, Eggman uses his built-in command grab
In 2015, it was revealed that Ian Flynn, Tracey Yardley!, and Ben Bates of Archie Sonic the Hedgehog fame had pitched a line of Super Mario comics to Nintendo. It was ultimately rejected. Allegedly, Mario was also intended to cross over with Sonic and Mega Man in comic form.
Knuckles the Echidna's father dies of pancreatic cancer in the Archie Comics.