Perhaps in a nod to fans wanting an unannounced Undertale 2, the creator comments that he purposefully framed the world of Deltarune to ' make it seem like Undertale.' The build of Deltrarune Chapter 1 played on the stream also contained several unique Easter eggs not present in the consumer release, as NPCs like Birdly make fourth-wall-breaking references to the real-world event and a birthday cake with the number six at its center could be spotted sitting on a shelf in the background of Seam's shop.
Fox talks about a variety of inspirations for Deltarune throughout the broadcast.