Very beautiful sonorities. Are you a fan of Joe Hisaishi, by any chance?
The comments regarding the samples are bang on target. A piece this lyrical will always be let down by samples with next to no decay (plus no reverb). Also, this seems to be a mono rendering - stereo would be very nice.
Onto the material itself: the clarinet at 1:37 may be drowned out in a live performance, so consider bumping it up and octave or turning it into something else (a horn, maybe...although that wouldn't bode well with the higher notes that follow). Loved the piano passage at 2:50. Try not to have too much going on in the same register, as it gets a little bustling at times.
I do think you need to develop your ideas a little, although at the same time I understand this is supposed to be incidental music. Regardless, see attached for one way in which you could elaborate on the existing material aside from cycling through the parts.