This page details one or more prerelease versions of Undertale.

To do: Rearrange the entire page, and put the separate post-release beta/conceptual stuff in a different article. A full playthrough of a prototype of the demo, a few weeks before the demo's public release. Miscellaneous prerelease information: [1], [2], [3], [4], [5], [6], [7], [8], [9], [10] Concept art that Toby forgot to put in the art book: [11], [12], [13], [14] Very early concept art/notes: [15], [16], [17], [18], [19], [20], [21], [22] https://twitter.com/tobyfox/status/894942027389038593

Development Timeline

2013

• February 4: Toby Fox replies to a member on Starmen.net, and shows the very first image of "Underbound 2", actually from an early version of Undertale.


• May 2: An earlier version of the demo is showcased in a Fangamer stream.


• May 23: The demo of Undertale was released to the public.


• June 24: The Kickstarter page for Undertale opens.^[1]
  


• July 24: The Kickstarter page for Undertale is closed, having raised a grand total of $51,124.^[2]
  

2014

• February 21: Toby Fox states that the game is "approaching 50% completion", but hasn't had much time to program the game due to schoolwork causing development to go on hold.^[3]
  


• May 3: Development of the game resumes, as Toby Fox graduates from university. Additionally, a Korean version of the demo is released.^[4]
  


• June 25: Toby Fox reveals that "Area 3" of the game (actually Waterfall) is complete, and claims that "Area 4" (ie. Hotland) will be the last one finished.^[5]
  


• August 31: "Area 4" of the game is halfway complete, and Toby shares some other progress in the game itself.^[6]
  


• October 30: "Area 4" is mostly complete, with some glitches being fixed.^[7]
  


• December 18: Toby Fox finally finishes Asgore, which he claims to be the "final boss" of the game.^[8]
  

2015

• January 15: A new trailer is released on Steam Greenlight.^[9]
  


• February 22: A small update is released, stating that since the last one, "an ending", "the last date", "a very pathetic shopkeeper", and "a nice place with a shower, air conditioning, and a bunch of fun movies to watch" have been added.^[10]
  


• May 1: Toby Fox sends a late build of Undertale to some select backers, which plays like the normal game except for a couple of missing features, like "one ending not being beatable".^[11]
  


• May 30: By this point, the last ending is "almost complete", with only one boss in the route being unfinished. Various other minor things were added.^[12]
  


• June 30: Since the last update, Undertale has been mostly converted to Game Maker: Studio; as a result of this conversion, the instruction manual was left unused.^[13]
  


• July 30: Toby Fox claims that the game is almost complete and mentions a "possible August" release.^[14]
  


• August 22: The game's release date is unveiled as September 15, 2015.^[15]
  


• September 8: Toby Fox posts the release trailer of Undertale, one week from the game's release.^[16]
  


• September 15: Undertale is released.

Pre-Development

In December 2012, Toby Fox started to develop Undertale after he clicked on a random article on Wikipedia and ended up on a page about arrays. Back then, he studied about basic programming variables in RPG Maker 2000 by reading books, but he did not know how to code a full-scale game. The game's original idea dating back to early 2012 ended up being released in 2018 as Deltarune

He stated in an interview that the "Action" and "Quit" commands were inspired by Shin Megami Tensei, in a same vein to interacting with monsters.

Starmen.net Reveal

On February 4th, 2013, Toby posted a joke reply in a friend's forum thread on Starmen.net, in which he claimed to be working on a sequel to the (likely also a joke) EarthBound hack UnderBound, titled UnderBound 2. The images and music shown were, in reality, from an early version of Undertale, and feature several differences from their final versions.

TestMonster? All I see are Froggits!

The image on the right shows the earliest revealed screenshot of the game. While most of it looks similar to how the final game looks, the options at the bottom are different, with a "Talk" choice instead of "Act", "Spare" instead of "Mercy", and a "Spell" option that's not in the final (its graphics are present but unused, however). No visible LV meter has been implemented. The Froggit enemies are called "TestMonster", and the spots on its chest are slightly different than the final's.

Frisk originally had black outlines and darker hair and shoes. This was changed to a lighter brown in the final.

The regular battle theme, "Enemy Approaching", was one of the earliest tracks written for the game. The version from the PK Hack thread is slightly incomplete, notably missing the outro the final has and the beep-y instrument from 0:21 on.

Pre-release	Final

Compared to the final, the early version has blockier graphics. LV is next to the player's name, and there is an extra stat EN, which Toby says stands for English, though more likely stands for Energy, which is a unused stat in the demo's code.

Pre-release	Final

Dated April 5th, 2013 (one month before the demo release), this leaf puzzle was made a bit easier in the final version. Other parts of the ruins were also lacking markings or cracks on the ground at this point.

Toby testing stuff out (February 8th, 2013). The font used is wider than in the final.

The room shown here still exists in the final as "room_overworld", but the textures used were deleted, resulting in black space.

Happy Toriel with no horns. The original Boss Monster design lacked horns, but they were added because Toby felt it made them look too much like mimigas from Cave Story (a noted inspiration).

Sad Toriel with no horns.

Tem Shop Sprite

It's the Temmie Shop in a overworld sprite form.

So Sorry Front Overworld Sprite

Temmie Chang made an overworld sprite of So Sorry from the front, but it was not used and So Sorry is only seen from the back outside of battle.

Mettaton Essay

On Toby Fox's Twitter, he notes that at one point, Mettaton would save your essay to the hard drive as an image, but it was buggy, and thus was removed.

Bandcamp Demo Soundtrack Differences

To do: The "Start Menu" combines four tracks into one for some reason. Split this track up and compare it to the unused "Start Menu" tracks in the demo. The final game's Bandcamp soundtrack has differences in it as well.

The demo's soundtrack on Bandcamp features a few musical differences compared to the demo.

Fallen Down

This track is used when you first meet Toriel. The Bandcamp version is a slowed down, lower-pitched version of the demo's version in the files, which in turn is slowed down, and lower-pitched ingame.

Hotel Battle Music Prerelease Name

The song on the OST Can You Really Call This A Hotel, I Didn't Receive A Mint On My Pillow Or Anything was named Hey This Wasn't Really What I Was Expecting From a Hotel, For Example You Didn't Even Leave a Mint on My Pillow when revealed in a Kickstarter update, and has the filename hey_this_wasnt_really_what_i_was_expecting_from_a_hotel_for_example_you_didnt_leave_a_mint_on_my_pillow.mp3 on Toby Fox's website. It was made on October 30th, 2014, at 8:58 AM.

Stronger Monsters WIP

This prototype version of Stronger Monsters is found on Toby's website, as well as in a Kickstarter update. The only major difference seems to be that the end is shorter. It was made on December 18th, 2014, at 8:16 AM.

Compare the end of this track with the final:

Unreleased Music

Various unreleased music tracks were posted to the Undertale Tumblr on the day before the game's 1-year anniversary.

Early Alphys

A calmer, less quirky-sounding version of Alphys's theme. It was rewritten for the final version because Toby felt it was too similar to "a certain lab song from another game".

Early Spear of Justice

An early version of Undyne's battle theme. Although the melody is mostly the same, it has a considerably more melancholy and less aggressive tone compared to the final version due to being written before Toby "really knew Undyne’s personality".

Early Undertale

An early take on the eponymous song. Compared to the final version, this is less bittersweet-sounding and is played in a minor key. Toby was inspired to change the guitar backing to a new melody (which itself served as the basis for Memory and His Theme) after hearing the song "Redline Day" from the 2009 anime film Redline.

Dog Hole

Definitely meant to be an area theme, but it doesn't sound quite like anything else on the soundtrack. Maybe that's why it was scrapped...?

"Dogtroid"

Dogsong arranged as a parody of the Metroid ending theme. Apparently, if you completed the game quickly enough, you would have gotten an image of the Annoying Dog in a bikini as a "reward":

Concept Art

Papyrus

Concept art for what appears to be an early version of Papyrus (based on the pose). According to Toby, the gray pixels are a result of resizing in Microsoft Paint, so this may not be what the original version actually looked like.

Grillby

Concept art for Grillby with commentary.

Burgerpants

Concept art for Burgerpants with some... colorful commentary. According to Toby, Burgerpants is the only character whose final design matches the concept art 1:1.

Marsh

Concept art for the marsh with some some choice words for cyan-lovers. The final version of this area has cyan water anyway.

Toriel

According to Toby, this is concept art for Toriel. This is also used in the "Beauty" border in the console releases; namely, the Switch version.

References

1. 
   ↑ UnderTale by Toby Fox » Updates — Kickstarter
   


2. 
   ↑ UnderTale by Toby Fox » Kickstarter Over... — Kickstarter
   


3. 
   ↑ UnderTale by Toby Fox » Progress paused for now... — Kickstarter
   


4. 
   ↑ UnderTale by Toby Fox » Development resumes... — Kickstarter
   


5. 
   ↑ UnderTale by Toby Fox » Area 3. Area 3! AREA 3! — Kickstarter
   


6. 
   ↑ UnderTale by Toby Fox » Mid-Area 4 Update — Kickstarter
   


7. 
   ↑ UnderTale by Toby Fox » Another Small Progress Update — Kickstarter
   


8. 
   ↑ UnderTale by Toby Fox » Merry Undertale, Again — Kickstarter
   


9. 
   ↑ UnderTale by Toby Fox » Undertale's on Steam Greenlight! — Kickstarter
   


10. 
    ↑ UnderTale by Toby Fox » Extremely Normal Progress Update — Kickstarter
    


11. 
    ↑ UnderTale by Toby Fox » Regular Progress Update — Kickstarter
    


12. 
    ↑ UnderTale by Toby Fox » Getting Closer... — Kickstarter
    


13. 
    ↑ UnderTale by Toby Fox » Small Monthly Update — Kickstarter
    


14. 
    ↑ UnderTale by Toby Fox » Hopefully Nearing The End Of These Updates — Kickstarter
    


15. 
    ↑ UnderTale by Toby Fox » Release Date — Kickstarter
    


16. 
    ↑ UnderTale by Toby Fox » UNDERTALE Release Trailer! 1 Week Away! — Kickstarter