The violin lead sounded nice, if not a little too thin for the piece. Perhaps adding some reverb and taking some high end off would make it blend better.
Otherwise, your chord progressions are beautiful and appropriate. When the string section comes in at 2:20-ish, watch your high end. It sounds like your lead is a bit too far ahead of the harmony. Maybe reverb lightly and push it somewhat into the middle of the ensemble. Those higher frequencies will stick out on their own.
Your piano synth is perfect for the piece, and it comes off as thoughtfully melancholy. Emotional expression is top notch.
Thanks for the review request!