Deltarune: Chapter 1 offers an immersive role-playing experience set in a vibrant world filled with monsters. Players take on the role of Kris, a human who, along with classmate Susie, finds themselves in the mysterious 'Dark World'. Here, they meet Ralsei, a character who reveals their destiny as heroes tasked with saving this unique realm. The narrative unfolds through engaging interactions and a whimsical storyline that captures the essence of adventure.

The game features a dynamic combat system that combines traditional RPG elements with bullet hell mechanics. Players can choose to confront enemies with violence or resolve conflicts peacefully, offering a unique approach to combat that encourages strategic thinking. As Kris, Susie, and Ralsei navigate the challenges of the Dark World, players encounter various beings known as 'Darkners', enriching the gameplay experience with diverse interactions and quests.