Gaemon - thanks for the advice. The stroke irregularities was just from my being lazy. I'm hoping to add some photoshop magic to the waterfalls to make them look more like flowing liquid, but I will wait to do that until after I finish the basic layout and texturing. Same with the transparent walls--it'll have to be 'post processing,' but I hope to get to it.

Good point about the stairs though. when things are face-on in Isometric maps, it destroys the perspective, doesn't it? I remember someone saying not to have rivers flowing directly "up" the map because it breaks the illusion.

Anyway, thanks for the compliment! I hope you join in on this challenge too!