the airy beginning reminds me of some old school video games. Once the bass and other stuff comes in it sounds good, but the stop-start rhythm feels a bit odd, at least being used as often as you do it. I think it'd work a lot better in moderation. As it is I feel like it just breaks up the entire flow, or feeling, of the song.
I really like the minimal bass playing. Simple. but its very effective here. Volume panning of the pads are a nice touch to the atmosphere too.
Ending was nice and added some good variety. Song feels like it went by a lot faster than its length. Didn't really feel like it established a definite mood for me though, but besides that it was pretty enjoyable.