It's 'cause I've increased the saturation in some of the RTP tiles. Not sure why, but I've been doing that a lot lately -- I'm trying to distinguish it a little from the standard RTP that Legionwood 1 used.
@Adon237: Well, it's probably not as obligatory as sewer dungeons, but all good RPGs have a desert sequence somewhere (and a forest one, and usually a mountain/canyon one as well) I try my best to check off all the old cliches ;)
@Dyhalto: Resemblance to any other map is strictly coincidental :)