Deltarune

Lore & Background

The inspiration for Deltarune came to Fox in a fever dream in 2011. Development initially began in 2012, but was abandoned before Fox created the first room. Temmie Chang, who had assisted with character art in Undertale, serves as the main artist. After the release of the first chapter, Fox expanded the team to assist with development.

The first two chapters were released together as a single free demo in 2018, with Chapter 2 added as a free update in 2021. As of 2025, only Chapters 1 and 2 are publicly available; no further chapters have been released, and the total number of planned chapters has not been officially confirmed. Initially released for macOS and Windows, it was later ported to the Nintendo Switch and PlayStation 4 in 2019. No ports to other platforms have been officially confirmed.

Reader's Guide

Deltarune represents a significant expansion of Toby Fox's creative universe, building on the foundation of Undertale while introducing a new setting, overhauled battle system with multiple party members, and episodic structure. The game has been praised by critics for its soundtrack, characters, narrative, and sense of humor. Its combat system is turn-based and uses bullet hell mechanics, and like Undertale, enemy encounters can be resolved peacefully or through violence. The game does not have a random encounter system; instead, players can see enemies in the environment before they encounter them. The second chapter introduced the ability to recruit enemies to live in the player's Castle Town. The game's episodic release model—with free demos for early chapters and a paid release for later ones—has allowed Fox to develop the story over time, with five of seven planned chapters released as of June 2026. The game's legacy includes its influence on indie RPG design and its dedicated fanbase, though its story remains incomplete.

Did You Know?

• The inspiration for Deltarune came to Toby Fox in a fever dream in 2011.
• The first two chapters were released as free demos in 2018 and 2021 respectively.
• The game features a turn-based combat system with bullet hell mechanics and a tension points (TP) gauge.

Origins & Development

The idea for Deltarune struck Toby Fox during a fever dream back in 2011, giving the project a somewhat mystical origin story. Fox began actual development work in 2012, yet the effort stalled so early that he never even completed the game's first room before shelving it. When the project eventually gained momentum, Temmie Chang—who had already contributed character art to Undertale—stepped in as the primary artist, lending the game its distinctive visual identity. After the first chapter reached players, Fox brought on additional team members to help manage the growing scope of the project. This small, tightly-knit creative core stands in contrast to the large studios behind most RPGs, and it explains why the game carries such a personal, auteur-driven feel. The fact that the concept gestated for years before Fox committed to it again suggests a developer who was waiting for the right moment to return to the world he had first imagined in a fever.

Gameplay & Combat System

Deltarune presents its world from a top-down perspective, splitting play between overworld exploration and structured combat encounters. In the overworld, players navigate environments, solve puzzles, gather items, and talk with NPCs. Each chapter introduces its own traversal twist—climbing sequences in one, or statues that flip the game into a side-scrolling 2D platformer with action-based combat in another. A key departure from Undertale is the absence of random encounters: enemies are visible in the environment, so players can choose to walk past them or deliberately engage. Combat itself is turn-based, offering a menu of fight, act, item, spare, and defend. During enemy turns, the player pilots a heart-shaped soul through a bullet-hell gauntlet. Grazing bullets—letting them pass close without being hit—builds a tension points gauge that fuels party spells, such as Ralsei's pacification ability. Spared enemies can even be recruited to settle in Castle Town, while defeated foes grant HP and magic to the party.

Narrative & Chapter Structure

Deltarune unfolds across seven planned chapters, with five released as of mid-2026. The story exists in a parallel universe to Undertale, sharing some characters and thematic DNA but occupying its own distinct setting. The player assumes the role of Kris Dreemurr, a human teenager who, together with the monster Susie and the dark prince Ralsei, is bound by prophecy to seal the Dark Fountains that sustain shadow realms. Chapter One introduces the tyrannical King and his son Lancer, while Chapter Two shifts to a computer-lab Dark World ruled by a laptop Darkner named Queen, who reveals that a mysterious figure called the Roaring Knight is responsible for creating the Fountains. The narrative carries a notably dark undercurrent: at the end of the first chapter, Kris rips out their own soul, locks it away, and draws a knife—only for their mother Toriel to scold them the next morning for eating pie with it. This blend of high-stakes fantasy and domestic comedy defines the game's tonal identity.

Release History & Critical Reception

Deltarune's release strategy was deliberately episodic. The first two chapters arrived as free demos in 2018 and 2021, building anticipation over a three-year gap. The paid full release in 2025 bundled chapters three and four, while chapter five followed as a free update in June 2026. Chapter six is slated for 2027, and a seventh chapter is planned for an unspecified later date. Platform availability expanded steadily: the game launched on macOS and Windows, moved to Nintendo Switch and PlayStation 4 in 2019, and then to Nintendo Switch 2 and PlayStation 5 in 2025. Critics have consistently highlighted the game's soundtrack, its memorable cast of characters, the depth of its narrative, and its sharp sense of humor as standout qualities. The free-to-paid model, combined with the multi-year cadence between chapters, gave Fox unusual creative breathing room while keeping the community engaged across nearly a decade of development.