Pretty decent, overall. It accomplishes the feel you were going for fairly well. It's not exactly my sorta thing, but I can't take off points for that. Now, what I would normally say is that there isn't much harmonic variety or progression and the entire thing drags on in a very similar fashion throughout, but I suppose that's reasonable in this sort of style. I do like the feedback-ish sound playing throughout the first half of the song and at the end. It's pretty much the only distinctly "electronic" sound you have here. I would try to enhance it in some way, maybe accentuate the lower frequencies. The hit at 1:06 was a nice transitional tool.
It has the correct ambiance, but (personally) I felt the meat of the song was lacking interest value. I could envision it being title screen music for a variety of game genres.
Please contact me if you would like to use this in a project. We can discuss the details.