It took me about an hour to figure it out but there is a controls.json file that you can edit. I am on linux so for me it was in home/user/.local/share/Celeste64/ and i think it might be somewhere in %appdata% for you if you're using windows.
I FOUND IT! Thank you very much, now I can play this in a comfortable way, for those who play on Windows, the file is at "C:\Users\AppData\Roaming\Celeste64\controls.json"
