Pretty good!

The main melody is lovely, and the atmosphere you paint with your synths is great. Akin to a modern trance track should be a much punchier and in-your-face kick drum, especially for a minimalist track like this. Some variation on the kick, especially between phrases and breakdowns wouldn't hurt either.

Your long buildup starting at about 2:50 could use some work, production-wise: The build up arp clashes too much with your ducking background pads, disrespecting the overall mix's sense of sound space. A filter to the pad or cutting back on the reverb/echo on the arp (as well as some good EQ'ing and peak-level compression) would do the trick.

Despite these nit-pickings, this is a very good track, and I hope these production/mastering tips will help you in the future.