The technique of using major chords borrowed from different keys gives this song an uplifting feeling that feels relaxing. At the same time, the offbeat marimba notes highlight a non-diatonic minor tone that adds tension allowing for a satisfying resolution in the way that functional harmony would. I think that brass has a round or smooth quality which makes this a great fit for a song trying to evoke a more relaxed sound. Great job and thank you for sharing!