This is a controller layout that suggests a layout for your controller that works in Desktop mode so you should just be able to play soot's browser version or itch.io client version with your controller with no extra shenanigens.

Controller Layout for Steam Desktop Mode

palex00

SOOT

wanyay

shizchiz

Soot's developer GartekStudios is running a speedrunning contest with cash prizes. First and second fastest time at the end of February get 50$ and 25$ respectively and everyone with a sub 30 time gets in a pool for 25$ (all CAD).

More Infos: 
https://gartekstudios.ca/