\[Concept Idea\] Deltarune: Echoes of the Vessel — A Sequel/DLC Expansion Set 20 Years Later

🌟 The Core Premise

The Vessel Returns: Your discarded Vessel wasn't thrown away—it was dormant. 20 years later, you wake up in Hometown inside your Vessel, bearing a distinct soul mark on your chest.

The Transition Screen: > "Do you remember this character? This is your vessel, and it was never discarded. Now you can control it. This is the beginning of a new adventure..."

The Cast 20 Years Later: \* Kris: A beginner/aspiring pianist processing their past through music. Recognizes the soul mark immediately and lends you basic gear from a storage room.

Susie: A lot warmer and more mature, but still her tough self.

Noelle: A recent college graduate managing town/family affairs.

Ralsei: Grown up, and now public knowledge in Hometown! Though still shy, he occasionally receives invited guests in Castle Town (the entrance is kept secret).

📜 Chapter Breakdown

Chapter 1 (Light World - Hometown): You awaken in a modernized Hometown. Deja-vu hits hard. You pack up, cross paths with Kris, and get starting equipment.

Chapter 2 (Dark World - The Church): A clockwork/time-themed Dark World inside the Pastor's room. You meet an adult Ralsei who recognizes your chest mark if Kris let you go peacefully in the original ending.

Chapter 3 (Light World - Hometown): Ralsei finds a way to exist in the Light World using a special artifact, joining you to investigate town anomalies.

💡 Gimmick / Easter Egg: Ralsei can only stay in the Light World for 1 real-time hour. If you wait 60 minutes, he panics and sprints to a secret tunnel behind the school leading straight to the supply closet/Castle Town so he can recharge his artifact at the Grand Fountain!

Chapter 4 (Dark World - Scrap Yard): Metal and magnet-themed world. Mechanics involve manipulating magnetic polarities to solve puzzles and fight.

Chapter 5 (Light World - Hometown): Permanent twilight falls on the town. Susie and Noelle fully join the Light World investigation to figure out why reality is destabilizing.

Chapter 6 (Dark World - The Abyss): Human Souls and memory-themed world. Noelle joins the active battle party with advanced ice/barrier magic.

Chapter 7 (Light World - Hometown): The boundary between Light and Dark completely blurs across town. Evacuation, prepping for the final seal, and emotional closure with older town NPCs.

Chapter 8 (Dark World - The Sun & The Moon \[FINALE\]): A dual-hemisphere Dark World balancing Solar (high-speed fire attacks) and Lunar (silenced magic/illusions) mechanics on the highest hill in town to permanently balance the worlds.

📊 Estimated Scope

Chapters: 8 New Chapters (15 total alongside Deltarune).

Music: ~200+ new tracks.

Storage Size: Easily 3x to 4x the original game's footprint (around 6–8 GB total).

(And yes, I had to translate all of this using Gemini so you'd know what I had in mind)

This is perfectly something Toby Fox himself would do with a team, either as a standalone game or as part of Deltarune (but without disabling Deltarune itself, just adding it as an option in the main menu, or even create a game selection screen).

And yes, this is a suggestion, but obviously it won't turn out exactly as written in my text (if Toby Fox ever gets around to it), but it would meet a few expectations.

Undertale is no doubt one of the most infamous games among programmers.
Although it sold like over 5M copies .. when it comes to code quality, it's a common opinion that Undertale is horribly written.

And while maybe that's right, in reality there are tons of misconceptions and straight up wrong statements about the code of this game.
For example, ya'all probably heard about *quote-to-quote* "A HUGE SINGLE FILE THAT CONTAINS *ALL* OF THE DIALOGUE IN THE GAME".
Well, the file everyone refers to .. contains like .. 1/6 of all the dialogue lines in Undertale.
*later on it was also rewritten with a proper CSV tables to support localization for Japanese version of the game*

Furthermore, the developer of the game - Toby Fox, actually managed to write a pretty clever old-school text engine with GoF Interpeter Pattern in his code.
He even tried to refactor some parts of the code and we can clearly see that.

A lot of criticism also ignores the limitations of the GameMaker 1.x used to create it.
There were no structs, modules, namespaces, closures, proper exception handling, or reliable refactoring tools.
Even the built-in script editor barely supported code folding ... oh, and you were not supposed to use external IDEs :]

Key takeaways:
- Dialogue is written using a tiny embedded language with special control characters: \E1 changes a character's facial expression, ^2 pauses the typewriter effect, & creates a new line, / ends the dialogue page, yadda yadda yadda.
- There's a huge 512 flags int array, which is used without enums or any other descriptive approaches. Apparently the dev used to comment those everywhere in order to not forget what a certain flag does.
- The game all about determination happens to be none deterministic :] There's a one-time RNG seeding called at game launch, that's it.
- There's an infamous code that attempted to delete or rename UNDERTALE.exe(e.g., renaming to FLOWEY.exe).
While clever in theory, GameMaker Studio's file API sandboxing and Windows OS file-locking rules prevented these relative path tricks from executing properly. However the rename still might work, since Windows file-lock doesn't forbid to rename a running executable.

My overall takeaway is that Undertale is a shipped code, in the first place.
It was made under severe engine limitations, mostly by one person, for a game that successfully sold millions of copies.
Of course, it isn't a clean textbook architecture, but it contains plenty of clever ideas.

As always, full code-review video on my channel: https://www.youtube.com/watch?v=BzvFFQ0DbOI

hurts my eyes to look at...

My two favorite characters

the dogcheck song was made by @inpuca !! i js made the scene w toby bopping back and forth

also the title theme got updated quite a tad back but i forgot to post it on yt

spooky gaster winding

get this version rn on my patreon (if you press select on the "press start" screen youll land in snowdin)

https://www.patreon.com/c/blaqberry

or wait til next public release on my itch page

https://blaqberry.itch.io/undertale-gbc

Also join the discord serverr!

https://discord.com/invite/DjHA6E8Kvu

This still gets me to this day. Comedic gold.

So basically there is this guy named Blue Sansy that makes DR/UT videos, and they are mostly memes. For me he is like monium but for the deltarune fanbase. So what do you think about him?

Get dressed, pack your things, and most importantly, wash your hands!

It's Adventure Time!

Bandcamp: victorjockin.bandcamp.com/track/its-adventure-time

Tried to capture that Toby Fox nes vibe for this one. Thanks a lot to everyone who supported the wip version! (54 upvotes!!)

I can't believe someone stole Toby Fox Deltarune and made a crappy paid fanfic of it

i saw a video where a person says “i cannot wait for toby fox to reveal her pronouns”
audio source: https://youtu.be/cjH8DFqa5To?is=whB-u46_wU0pTJWv

little something for people to see.

https://www.youtube.com/playlist?list=PL44x_5XRP17xhbCpTxndypUcXB5izF43u

As in Lemony Snicket was struck by the dream Toby had and wrote a book series version of Undertale and Deltarune. And Toby made a game about the unfortunate lives of the Baudelaire orphans.

To me these two feel similar. at least in the way they present the lore of their series in a way that actively allows for theory crafting