
After revolutionizing gaming with Undertale, Toby Fox introduced Deltarune, further developing its essential elements. Although not a traditional sequel (or prequel), Deltarune is a spiritual successor offering a parallel narrative to Undertale, while maintaining common themes and characters in a distinct continuity. Yet, Deltarune retains the peculiar, distinctive role-playing style of Undertale, inviting players into a mystical land called the Dark World where they confront diverse creatures in turn-based combat infused with bullet-hell elements-even allowing players to opt for either fighting or sparing enemies, as in Undertale. Chapters 1 and 2 were released in 2018 and 2021, while Chapters 3 and 4 debuted on June 5, 2025, on Nintendo Switch 1 and 2, PC, and PlayStation platforms.