Toby Fox unexpectedly releases the first chapter of Deltarune for free. The game shares similarities with Undertale but is presented as a separate, albeit related, project.

Toby Fox and a larger development team work on subsequent chapters of Deltarune. Development is slower than Undertale due to increased scope and complexity.

Chapters 2 of Deltarune is released for free.

Toby Fox has stated that he is working on Chapters 3, 4, and 5 of Deltarune and is actively developing these future installments.