I didn't find anything that clashed. It's a good song.
But I did feel that it wasn't very adventurous harmonically.
I guess the only thing I can do is suggest a few things, and you can take or leave them any way you want...
That same chord progression kept repeating the whole time, I would suggest changing it up somewhere in the middle, it feels kind of stale after a while.
Or if you feel like the piece isn't supposed to change harmonically, then perhaps do more with the orchestration. You can pass the arpeggiated line around the orchestra, have instruments come in and out so that it is one seemless continuation of the line, but it keeps changing colors.
You've done some cool stuff where you change instruments and add new ones. Maybe try combinations of instruments and see what you can get out of that. I think working with the orchestration will really take this piece to the next level.