#sth3&k

So in the IDW Scrapnik Island Comics we Sonic and Tails end up on Scrapnik Island which contains the Death Egg from Sonic The Hedgehog 3 & Knuckles. We also, see Scrapnik Mecha Sonic remembers the events of STH3&K as well. As we know the IDW Comics are canon thus this further confirms the Classic games did happen in Modern Sonic's past. Written by Eris

So in one of the cutscenes for Sonic The Hedgehog 3 & Knuckles we get to see that the canon ending to this game, is the one where you collect of the Super Emeralds and become Hyper Sonic and fight Eggman in Doomsday Zone.

Also, Sonic Channel's Super Sonic info says the following about STH3&K. "By collecting all the emeralds in the main game, you can transform into Hyper Sonic, which is even more powerful than Super Sonic."

So yeah Hyper Sonic is canon, however it doesn't show up anymore to avoid DBZ comparisons from what has been stated. An in-universe explanation could be that the Chaos Emeralds must be charged up into the Super Emeralds by the Master Emerald, and Knuckles doesn't let Sonic do this as he himself won't use the Master Emerald for himself.

Extra note, while it was claimed that the Hyper Forms aren't canon this wasn't ever actually said. The claim originates from GeneHF on Sonic Retro's discussion boards, the one titled Sonic Runners announced (Sonic Team/Mobile) which was started Dec 28, 2014. Credit to definitivedubs post on Sonic Retro under the title "Only male hedgehogs can turn Super" made Feb 21, 2023. As they are one was able to find where this claim originated. So GeneHF claims that "The Super Emeralds and the Hyper forms are non-canon. They may never be referenced again." They also claim that this is from the Sonic Bible and that Iizuka said this stuff publicly, but provide no source. Note, I'm not addressing the Sonic Stadium stuff because that literally leads nowhere. Written by Eris

So in Sonic Frontiers there is a scene where after seeing some structures, Knuckles remembers the events of Sonic The Hedgehog 3 & Knuckles. This scene further confirms the Classic games are indeed Canon to the modern games. Written by Eris

So many people have questioned whether or not Mecha Sonic actually went super in his fight with Knuckles in Knuckles' story from Sonic The Hedgehog 3 & Knuckles.

So in an IDW Sonic Comic featuring the Classic Characters Sonic taunts the rebuilt Heavy King, by making fun of the fact he can't go super yet Mecha Sonic could. This confirms Mecha Sonic did indeed go super. Written by Eris

In Sonic The Hedgehog 3 & Knuckles in Sandopolis Zone you can see depictions of humans thus an acknowledgement of other humans can be found this far back in the games.

The same goes for Marble garden Zone with some traps using humans faces in the design also show up. Written by Eris

So we all know the Echidnas have some connect to the pyramids and possibly Egypt in the Sonic world as seen in Sandopolis Zone from Sonic The Hedgehog 3 & Knuckles, and Pyramid Cave from Sonic Adventure 2.

But turns out Hedgehogs also have these connections too. In Sonic The Fighters we get to see a Hedgehog Sphinx in a desert surrounded by pyramids. Written by Eris

In spite of it's many problems, there is Sonic Prime is intended to be canon to the games. Thus, there reference to the events of Sonic The Hedgehog 3 & Knuckles in Sonic Prime further confirm the Classic games are Canon. Written by Eris