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Rouxls Kaard's line "Lost...? Frightened...? Confused...? GOOD!! HA HA HA!!!" appears to be a reference to the 1995 edutainment title I.M. Meen, in which the eponymous antagonist says a similar line.
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In the livestreamed playthrough of Chapter 1 conducted for Undertale's sixth anniversary, it was revealed that Lancer's childlike characterization was originally far more subdued. Toby Fox later chose to exaggerate these elements after playtesters instead assumed that Lancer was a Danny DeVito-esque adult.
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These changes are also present in a mockup of the interior found in the game's files. However, the mockup is set during the day instead of at night, and the painting beside Toriel's chair is moved upward. This implies that the nighttime version of the interior was based on the mockup (with only minor touch-ups) without cross-referencing the layout seen earlier in the game.
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The Cutting Room Floor article:
https://tcrf.net/Proto:Deltarune/Chapter_1_%26_2_Demo_(2021)/Unused_Graphics#Kris
YouTube video showcasing the cutscene as it normally occurs:
https://youtu.be/Q4VJEHKBtlA?t=5228
https://tcrf.net/Proto:Deltarune/Chapter_1_%26_2_Demo_(2021)/Unused_Graphics#Kris
YouTube video showcasing the cutscene as it normally occurs:
https://youtu.be/Q4VJEHKBtlA?t=5228
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In the Undertale sixth anniversary livestream, Toby Fox stated that the scene in Chapter 1 where Susie holds off from attacking Kris due to her respect for Toriel was inspired by a real encounter with a bully that he had. According to Fox, the bully knew his mother and stated that they would've beaten him up if she wasn't nice to them.
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While the text initially parroted the phrase "THIS NEXT (space) EXPERIMENT (space) SEEMS (space) VERY (space) VERY (space) INTERESTING" from the unused room_gaster event in Undertale, by July 1, 2016, the text was edited to read "THREE HEROES APPEARED (space) AT WORLD'S EDGE", later being edited again by August 17 to say "THREE HEROES APPEARED (space) TO BANISH THE ANGELS HEAVEN". Both revisions quote portions of the legend that Ralsei recounts in Chapter 1, indicating that these parts of the game's backstory were already conceived by this point.
Following the release of Chapter 1, deltarune.com would be refurbished as the official website for Deltarune itself. Consequently, earlier versions of the site only survive through snapshots on the Wayback Machine, a URL archiving platform hosted by the Internet Archive.
The Cutting Room Floor article:
https://tcrf.net/Prerelease:Deltarune
Comments section and screencap of the now-deleted r/Undertale post:
https://www.reddit.com/r/Undertale/comments/3vxmhq/dreemurr_31_faq/
https://tcrf.net/images/d/db/Deltarune-dreemurr-com-originally-deltarune-com.png
December 9, 2015 Wayback Machine snapshot of him.png:
https://web.archive.org/web/20151209013205/http://www.deltarune.com/him.png
July 1, 2016 Wayback Machine snapshot of deltarune.com (Note: this archive is not displaying correctly as of May 13, 2024):
https://web.archive.org/web/20160817183540/http://www.deltarune.com/
August 17, 2016 Wayback Machine snapshots of deltarune.com and him.png:
https://web.archive.org/web/20160817183540/http://www.deltarune.com/
https://web.archive.org/web/20161221070931im_/http://www.deltarune.com/him.png
Tweets by @ChristopherMoom:
https://twitter.com/ChristopherMoom/status/1334580988521934850
https://twitter.com/ChristopherMoom/status/1334562885461307395
https://tcrf.net/Prerelease:Deltarune
Comments section and screencap of the now-deleted r/Undertale post:
https://www.reddit.com/r/Undertale/comments/3vxmhq/dreemurr_31_faq/
https://tcrf.net/images/d/db/Deltarune-dreemurr-com-originally-deltarune-com.png
December 9, 2015 Wayback Machine snapshot of him.png:
https://web.archive.org/web/20151209013205/http://www.deltarune.com/him.png
July 1, 2016 Wayback Machine snapshot of deltarune.com (Note: this archive is not displaying correctly as of May 13, 2024):
https://web.archive.org/web/20160817183540/http://www.deltarune.com/
August 17, 2016 Wayback Machine snapshots of deltarune.com and him.png:
https://web.archive.org/web/20160817183540/http://www.deltarune.com/
https://web.archive.org/web/20161221070931im_/http://www.deltarune.com/him.png
Tweets by @ChristopherMoom:
https://twitter.com/ChristopherMoom/status/1334580988521934850
https://twitter.com/ChristopherMoom/status/1334562885461307395
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Deltarune - Secret tree rooms featuring "Man":
https://www.youtube.com/watch?v=BYbzt3r97ZE
The Cutting Room Floor article:
https://tcrf.net/Prerelease:Deltarune/Early_Development#fwugradiation_Tumblr
Toby Fox's Tumblr post:
https://fwugradiation.tumblr.com/post/20325508850/made-up-yume-nikkis-dark-tunnel-amphitheater
https://www.youtube.com/watch?v=BYbzt3r97ZE
The Cutting Room Floor article:
https://tcrf.net/Prerelease:Deltarune/Early_Development#fwugradiation_Tumblr
Toby Fox's Tumblr post:
https://fwugradiation.tumblr.com/post/20325508850/made-up-yume-nikkis-dark-tunnel-amphitheater
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In Volume 5 of his Famitsu column "Toby's Secret Base", creator and director Toby Fox revealed that Ralsei's name came from a period in elementary school where he and his brothers constantly experimented with RPG Maker, having long had a shared interest in game development. Fox's oldest brother spent years working on a game called New Genesis, which featured a protagonist named Ralse; Fox simply appended an "i" to the name when incorporating it into Deltarune years later.
In the same column, Fox stated that the prolonged development of New Genesis discouraged him from making games for a long time. When he finally returned to the field in his teenage years, he sought to temper his expectations from the outset by making smaller-scale titles and preemptively planning out his approach to development to avoid biting off more than he could chew.
In the same column, Fox stated that the prolonged development of New Genesis discouraged him from making games for a long time. When he finally returned to the field in his teenage years, he sought to temper his expectations from the outset by making smaller-scale titles and preemptively planning out his approach to development to avoid biting off more than he could chew.
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After Queen realizes that she didn't capture Ralsei out of all of the Lightners due to not having enough cages, the sound effect that plays with the Iris Out zooming in on her face is the same sound effect used on the Iris Out on Mario when completing a level in Super Mario World.
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Toriel will also mention a related incident in which Asgore painted green spots on eggs as part of a birthday party for Asriel themed around the lizard (referencing Yoshi's eggs). The following morning, Asgore cooked the eggs for breakfast, which upset Asriel enough that it caused him to hate the book about "eating green eggs". This is a nod to the Dr. Seuss book "Green Eggs & Ham".
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Catti and Catty's dad in Deltarune:
https://www.youtube.com/watch?v=zZw4H1K0YUg
Doug - Mr. Dink's grill scene:
https://www.youtube.com/watch?v=jVkEd2FWxdk
https://www.youtube.com/watch?v=zZw4H1K0YUg
Doug - Mr. Dink's grill scene:
https://www.youtube.com/watch?v=jVkEd2FWxdk
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