Deltarune

Deltarune is a role-playing video game. It was created by American indie developer Toby Fox.

In the game, the player controls a human named Kris. The game is set in a world where monsters live on the surface of the Earth. Kris and their monster classmate, Susie, fall from Earth into a place called the "Dark World," where they meet a prince named Ralsei. Ralsei tells them that the three of them are heroes destined to restore balance to the world. Through the fighting system, the player meets different enemies who attack by shooting small missiles which the player must dodge (a video game genre known as bullet hell). These encounters can be resolved peacefully or by fighting back. Deltarune is a spin-off of Fox's earlier game, Undertale. The game has many of the same characters and settings from Undertale. But, according to Fox, the games are not set in the same world.

The first chapter of the game was released on October 31, 2018 for Microsoft Windows and macOS. A version for Nintendo Switch and PlayStation 4 was released in February 28, 2019. The second chapter was released on Windows and macOS in September 17, 2021. The third and fourth chapters came out at the same time on June 5, 2025, along with the release of the Nintendo Switch 2.^[2] These chapters costed money, unlike chapters 1 and 2, which were released for free.

The graphics of the game are similar to 16-bit Japanese role-playing games such as EarthBound, Mario & Luigi: Superstar Saga and Chrono Trigger.^[3]

Similar to Undertale, Deltarune is a role-playing game that uses a top-down perspective. The player controls a human named Kris. They have to complete objectives in order to progress through the game. When fighting, the player can choose the actions of their party members.^[4] Combat in Deltarune is similar to other turn-based role-playing games. Players can choose from a set of actions such as Fight or Spare. The game also has TP (Tension Points). These can be used to allow team members to use spells such as Ralsei's Pacify spell.^[5]

Upon starting the game for the first time, the player is allowed to create an avatar, referred to by a weird voice as a "vessel". After making this vessel, it is deleted, with the player being told that "No one can choose who they are in this world".

The player begins with the story controlling Kris, a human who lives with their adoptive mother Toriel, a goat-like monster. Toriel drops Kris off at school, where Kris goes to a class taught by Alphys, a lizard-like monster. Susie, another lizard-like monster who is Kris' classmate, is sent to get chalk for the blackboard from the supply closet along with Kris. After Kris and Susie enter the supply closet, both of them are pulled into the "Dark World". There, they meet Ralsei, a prince of the dark, who tells them that the three of them are heroes destined to close a geyser of dark energy (Called a Dark Fountain) to restore balance to that world. However, a Darkner (Person who lives in a Dark World), King, has seized control of the Dark World and is determined to spread darkness.

Susie chooses not to help, only wanting to return to her own world. However, the three encounter Lancer, King's son, who tries to stop them from getting further with various poorly thought out plans. Susie eventually decides to join Lancer, leaving Kris and Ralsei on their own. As Kris and Ralsei make their way to the King's castle, Susie makes friends with Lancer, and the four eventually become a team. Upon realizing that they will have to face the King, Lancer runs off to the castle and tells the King's henchmen to throw Kris, Ralsei, and Susie into the dungeon.

Susie escapes the dungeon and confronts Lancer, who explains he wanted to keep Susie and the King from hurting each other. Susie promises Lancer she won't hurt the King. Kris, Susie and Ralsei go to the top of the castle and battle the King. Eventually, the King falls to the ground in exhaustion and Ralsei heals him. However, this is revealed to be a ruse as the King quickly stops the three heroes from being able to act, threatening to kill them all. If the player has not ended previous battles by fighting throughout the game, Lancer turns the King's men against him and imprisons him, taking his father's place. Otherwise, Ralsei subdues the King with a magic spell.

The group closes the Dark Fountain, so Kris and Susie can return to their own world. There, Susie says goodbye, mentioning that she wants to go to the Dark World again. The player can explore the town before having Kris go home to bed.

That night, Kris, without player input, shakes in bed, then falls on the floor, and limps to the center of the room. Kris tears into their chest and rips out their soul, throwing it into a birdcage in the corner of the room. Kris draws a knife and turns toward the viewer. They smile, with their right eye flashing red.^[6]

The day after Chapter 1 takes place, it is discovered that when Kris pulled out the knife, they had only did it to eat an entire pie. Kris meets up with Susie outside of the classroom after class and revisits the Dark World, after being invited to study in the library by Noelle. While in the closet, confused, Susie asks where everyone is. Ralsei asks Kris to gather the objects from the abandoned classroom and move them into the closet. After doing this, Castle Town becomes populated.

When Kris goes to leave, Susie complains about the group project, only to have Ralsei banish them from the closet until they start it. When they arrive at the Library (misspelled in the game as "Libarby"), they enter the computer lab and find another Dark World. There, they reunite with Ralsei, and meet Queen, the main antagonist of the chapter. The party then sees Noelle captured by Queen, and end up playing against Queen in an arcade game similar to Punch-Out!!. The group explores Cyber Field.

Queen eventually captures everyone, but Kris and Susie end up getting out and get Berdly to switch sides before later coming back together with Ralsei. Queen reveals that the Dark Fountain was created by an person known as the Roaring Knight, and that she wants to make Noelle to open a Fountain, which any person in the Light World (the "normal" world) can do. She threatens Noelle and the party with a giant mech, but they manage to make her realize how she was wrong. Berdly then tries to create a Fountain, but Ralsei warns him that opening too many Fountains will cause an apocalyptic "Roaring".

Kris closes the Fountain, and everyone wakes up in the computer lab in the Library. Noelle and Berdly say the events as just a dream. Kris heads home and Toriel invites Susie to stay at their house. While Susie and Toriel are making pie, Kris secretly rips out their soul, locks it in the bathroom, and shortly leaves the house off-screen. Toriel's finds her car tires with slashes in them, making her call the police. After everyone else falls asleep, Kris rips out their soul again and creates a Dark Fountain in the living room by stabbing the floor with their knife.

Kris and Susie wake up in the Dark World Kris created last chapter. After reuniting with Ralsei, they meet Tenna—a Darkner created from Toriel's television—who convinces the party to play in different game show segments. Sneaking away from Tenna, the party discovers Toriel being held hostage by Tenna inside of a giant toy capsule.

The party demands that Tenna stop the games, allowing them to seal the fountain and return home with Toriel, but he says no. Feeling abandoned and useless, he explains that the Roaring Knight promised him popularity in trade for keeping the Fountain open. After the party defeats Tenna, Ralsei and Susie comfort him, explaining that he has already spent years bringing joy and can find love and appreciation in another household.

However, he is suddenly attacked by the Knight, who also attempts to capture Toriel. The party then fights the Knight and is eventually defeated no matter what, only to be rescued by the arrival of police officer Undyne, who the Knight kidnaps. Kris and Susie chase the Knight through the Light World until reaching a locked bunker which appears to have a Dark Fountain inside of it. The door shuts before they can enter, but they discover a lock requiring three numeric codes. Susie runs back to Kris's home to rescue Toriel. The chapter ends with the bunker door opening in front of Kris.

After Kris and Susie close the living room Fountain that was in Chapter 3, Toriel wakes them and they go to church. Asking neighbors about the bunker, the two end up with the information that their best idea on the codes is Noelle's mother, Mayor Carol Holiday. They visit the Holidays' house, where Susie distracts Noelle while Kris searches. In the bedroom of Noelle's missing sister Dess, Kris finds a code in a guitar, but Kris rips out their soul before it can be fully read. The player-controlled soul enters the house's ventilation, finding Kris on the phone with an unknown person who talks about the Roaring Knight's actions and tells them to stop Susie from getting the guitar. Kris fails to stop Susie finding the guitar and returns the soul to their body, but Carol returns home and bans Susie from the house before she can memorize the code.

When they come back to the church, Kris and Susie find it became a Dark World that has parts of the prophecy. In the Dark World, they reunite with Ralsei again and find an old man formed from the ashes of dead Light World person Gerson Boom. Ralsei shares that he has been hiding parts of the prophecy from Kris and Susie because he believes the truth would be too upsetting.

The party encounters the Roaring Knight, who opens a Fountain within the Dark World, creating a "Titan", something that help brings the Roaring. The party defeats the Titan with help from Gerson. Against Ralsei's protests, Susie runs ahead and sees the ending of the prophecy. She smashes it like glass before the player sees, saying it was something the party would never let happen. After sealing the Fountain, they return home to find Toriel drunk with the grocery store janitor, Sans. Susie leaves and Kris, alone in their bedroom, is reminded by the unknown caller on their phone of a promise Kris made.

Deltarune was developed by Fox in GameMaker Studio 2.^[7] The game introduces a new battle system influenced by the Final Fantasy franchise, contrasting with the original game's combat system (which was inspired by that of the Mother series). Some of the music in the game remixes much of the soundtrack of Undertale, but most pieces are new. The main game uses sounds from EarthBound, while battle music is similar to Breath of Fire III music, and even Lancer's theme is similar to J.A.K.Q. Dengekitai's opening theme. The game also has many similarities with Undertale in the name of characters, for example, Ralsei is an anagram of Asriel (a character from Undertale) and Kris (the main character from Deltarune) is almost an anagram of Frisk (the main character from Undertale). The name of the game, Deltarune, is an anagram of Undertale.^[8] Temmie Chang, who helped as artist on Undertale, served as the main artist for the game, designing characters, sprites and animations.

After previously teasing something Undertale-related a day earlier on Twitter, Fox released the first chapter of Deltarune, a game "intended for people who have completed Undertale,"^[9] on October 31, 2018 for Windows and macOS for free.^[10] Fox said that this release is the first part of a new project, and considered the release a "survey program" to determine how to take the project further.^[11] Fox mentioned that Deltarune will be a larger project than Undertale.^[12] He plans for Deltarune to have only one ending.