I really enjoyed the whole mariachi desert vibe to this track. The melody work was somewhat basic, but maybe that's the idea. Liked the horns, as well as the congos and percussion. The piano work was good, but after about 1:30 I wanted to hear more variation of melody - not necessarily any busier, just more variation. At 1:54 when you start to fade out the piano it felt somehow forced. Maybe some sort of a catalyst for the piano fade would work, after developing the melody for a bit longer.
The slow evocative feel of the piece gives it a lot of appeal - loved the howling coyote. The mix works fine, but there's this nagging thought in my head that its just barely too close and clear for the feeling you might be going for. When I think of the desert I think of vastness and distance; I wonder of your mix could reflect this more effectively. Like the piano fade, but more subtle. But this last point is really speculation on my part. I hesitated to put it in, but figured it's worth mentioning for a sense of perspective.