I have scientifically categorized key elements about Deltarune, so far.
>Source: dude trust me lol

>Fun
Chapter 2 > Chapter 1 > Chapter 4 > Chapter 3

>Music
Chapter 1 > Chapter 4 > Chapter 3 > Chapter 2

>Dumbass meme potential
Chapter 4 > Chapter 3 > Chapter 2 > Chapter 1