I enjoyed the arrangement quite a lot, someone else would be better commenting on the harmony, but the only improvement I would suggest right now is to adjust where the third instrument (violin) comes in, at 19 seconds. I found it quite jarring for this new part with the rest of the instruments coming in slightly later and not in time with the original beat. I don't know if you wanted to slow the piece down or create a more unexpected entrance for this instrument, which can work and I feel if you eased into it, it maybe could've worked a lot more smoothly.
It also happens at 31 seconds, might just be me who feels this, I still enjoyed the piece though :)