Celeste originally had a peppy, upbeat soundtrack similar to Kirby, says the game's composer

A portion of a Gamasutra interview with composer Lena Raine

GS: What thoughts went into creating the music for the harrowing climb that is Celeste? What makes a song feel appropriate to this kind of play experience to you?

Raine: My very first attempt at writing for Celeste actually overshot the goal for this quite a bit, but I think going a bit overboard let Matt & Noel close in on what kind of pace they wanted. My first attempt was super peppy & up-beat, something that wouldn't be out of place in, say, a Kirby game. It didn’t quite fit.

Celeste is a game about methodical planning as much as it is about action. I tried to keep the pace of the music lower in order to not stress the player out too much. Even the more fast-paced tracks that accompany chases or boss encounters have an intentionally lower tempo. They have a groove to keep you moving, but in a more slowed-down breakbeat sorta way.

from GoNintendo