The composition is lovely and very emotional. I really like the background instrumentation. That said, the instruments themselves sound a bit uncanny to me; they're not blatantly midi-sounding, but they don't sound very expressive either. There is a lot of emotion in this song thanks to the composition, but I think there's opportunity to enhance the emotion further by using more expressive instruments. I think a celeste could work well here; if you have kontakt, then you should already have a decent one.