Left ear: Scribble retrospective - death of Gaster
Right ear: Spookydood - 67 theory

I love this idea so much. We all want to see gaster SO much and the idea that the intended path is not to see him but because we break the route we get to see him in the weird route that would be so interesting.

There's one fundamental flaw in your reasoning regarding Kris's friendship with Susie: No, we didn't make friends with Susie by picking the right dialogue options. In fact, we could pick all the wrong ones and Kris and Susie still become friends. Kris befriends Susie in large part through actions we have no control over, like protecting Susie from King at the end of chapter 1.

Now, I still think Kris and Susie will end up having some form of conflict but I think Susie will take more issue with Kris keeping secrets and working with the dang knight than with our control

Interesting, but there is something that was overlooked. You actually CAN get the ThornRing without being locked into the Weird Route. Doing the Weird Route up to the point of getting the ring, you can avoid killing Berdly and get back on the Neutral Route with the Ring in your inventory. There's a lot of debate if this leads to an even more secret third route to the game, since Noelle won't be horrifically traumatized by the player but we'll still get our hands on the Twisted Sword.

By what was outlined, if it does unlock the ability to play as the Avatar we made at the start of the game, this would have to address Noelle not being murder happy and Kris utterly fucking despising us for causing that.

My main issue with this theory is that there is no indication that Gaster actually considers the weird route to be a deviation from whatever he's planning.
The route itself is implied to parallel the "evil route" from Dragon Blazers, which is based on Lord of the Hammer, which is based on the prophecy, and while Gerson himself never directly acknowledges the evil route's existence in the game, he does seem to consider it a valid adaptation, with its changes from the source material and all.
Basically everything Deltarune itself says about the weird route, directly or indirectly, seems to indicate that it is just as in line with "what's supposed to happen" as anything else.

i think a detail you missed is how gaster DOES intervene if he sees something interesting, if you do the knight fight (especially with no mantle) than gaster will comment on it and allow you to continue trying until you beat it/want to move on. Considering the fact that gaster never calls out the weird route at any point, even during the chapter 4 end, i believe he definetly wants us to do it and it is a planned part of deltarune in universe.

Lofi Gaster isn’t real he can’t hurt you.

Lofi Gaster:

"HOW MUCH LONGER NOW...?
MY DELTARUNE"

Goes so unbelivebly hard I cannot put It into words

i kind of disagree that the weird route is not intended by gaster. the playstation version of the game has achievements for beating each chapter that say "COMPLETE WITHOUT ISSUE" (and these were probably written by gaster). doing the weird route still gets you the trophy, the only thing that stops you from getting the trophy is getting the egg in that chapter, so it seems like the weird route is intended but the eggs are an "issue".

finally, a theory that makes the weird route morally wrong even in the context of the real world, so we can all hate ourselves for playing the game more effectively

GASTER is dead , we have killed (another) HIM - quote by some philosopher

The Twisted Sword can also be (presumably) obtained by aborting the weird route in Ch2 by just taking the Thorn Ring off Noelle and continuing as normal from then on, so you wouldn't actually need to go through the entire weird route to obtain the Twisted Sword unless the Ring somehow gets removed from you sometime during Ch5.

Papyrus is probably just not as social because he didn't have Flowey toying with him

Undertale anniversary 10 minigame if you do a genocide you get this message "you dint learn anything in 10 years? "

33:25 One thing i would like to note is that the prophecy is always displayed as capitalized to us. So it could in reality mean "love", not "LOVE", and sans makes a distinction of it in the last corridor.

I agree that the death of the author is a theme that Deltarune is leading up to, but I don't think it'll be the weird route which specifically causes it. I think the ending will be ambiguous as Gerson puts a lot of emphasis on making your own ending with the final book in his story never being written. We also don't see the final prophecy which in literal terms is obviously because we don't want to be spoiled the ending but symbolically I think it represents something open-ended.

I predict the game will end on an open-ended note, and we will be the ones who ultimately write the ending of the story via our own interpretations of what happens after. I think this will happen in both routes but in very different contexts. The normal route will lean more to a positive and transformative outlook while the weird route will lean to a more negative and destructive one. We will kill Gaster in this sense of writing our own ending rather than using the one he has planned out for us, whatever it may be.

Great theory, but one thing I notice is that according to the achievements for console versions (which appear to be from gaster) say you completed the chapter without issue even if you did the weird route, as though gaster had accounted for the weird route. If this were really breaking the game and gasters plan it probably would be noted as a problem. Instead I think the way to actually “break the game” would be something to do with the egg man, as finding him and getting the egg is the one thing that stops you from getting these achievements (potentially because its a problem for gaster). But all this is kinda a stretch so I could be very wrong.

18:25 *Through the boundless distance of parallel universes, you can almost hear... nostalgic sounds of file selection?

I liked the video and I think it is largely correct. But I'm not sure you were quite right about the "free will" theme. Something you should have looked at further in the section about Gerson is his letter to Alvin, and Alvin in general.

Alvin is someone who is worried about whether or not he lives up to his father's name, worried if he's doing the right thing, worried if his father is proud of him.

And it's not unlikely that he was the one who opened the initial church dark world given Ralsei's comments about "very specific darknesses" and the fact that the fountain is weirdly small compared to every other dark fountain we've seen in the game (including Susie's!), meaning someone else probably opened it besides the Knight. At minimum, it's very likely the hammer was planted there as part of someone else's plan.

So you have someone who's very worried about not living up to his father's legacy, maybe even manipulated into following a plan by someone else preying on his insecurities. And his father is telling him in his letter beyond the grave that it's OK to follow your own path in life: you don't need to follow someone else's path they created for you, even if you won't do everything perfectly on your own.

So I don't think Gerson's lessons are really about free will and not caring about the answer, so much as it is about realizing that you have more freedom than you might believe, even when you feel like you "have to" check certain boxes to fulfill your destiny. You lose sight of what's important.

And in general, I do think this theme is more well-supported than "free will". Susie breaks the rules. Ralsei says, "we have to do things this way" and Susie says "why?" and ends up making her own rules. Gerson recognizes this and sees in her the potential to reform the story into something better through hope.

17:38
Similarly, I don't rly agree that this is the case. This seemed reasonable enough pre-Chapter 3/4, but now I think it's not as well-supported anymore.

Or, to be clearer, I do believe Kris doesn't like being controlled, but I do not think our control what is weighing so heavily on them. The ending of the normal route chapter 4 could hardly be more obvious about this; the person who's really controlling them through all of this and dictating their actions is not us, it's whoever is on the phone (and imo it's simply just the Knight, not Carol, who isn't the Knight, but some may disagree with that). They have a choice to forge their own path with Susie or to keep listening to the voice on the phone.

Maybe Kris thinks they "have to" do all of this to avoid an even worse outcome. But if they weren't so focused on the prophecy, if they just had a little hope in their heart, they'd realize that there's always another way.

It is actually unclear if the weird route will let us make the twisted sword. I believe we won't be able to use thorn ring after equipping it to Noelle in the weird route. It has to be the abandoned weird route. Where we have the thorn ring, but we don't equip it. That is probably the game breaking thing.

Also sorely missing from this video is the analysis of the egg man. What does the egg man represent? As something that the author doesn't want us to engage with, but is still written into the game? What would be his fate?

Finally is there any evidence that Gaster is aware of the light world? I am not sure he has a connection to the light world as of yet!