But other than that the effect is very nice. The background movement could do with some tweaking, tho. First of all, y=d*r doesn't do anything since you don't have rectangular coordinates turned on, and you aren't using y in the r statement. You could also use a d=d/1.5 to get rid of the ugly line-repetition (doesn't work for windows much wider than 4:3). Also, the DM before that doesn't have to be a DM, since it's static. You could speed it up and get better resolution with a regular movement.
All in all I don't like the background, I think it could be much better. But this is pretty good for (what I assume to be) a first preset
Keep it up