@WNx Unrelated, what's up with that treeline? Trees generally don't tend to look good if they're all different sizes like that. Some of them don't even have trunks. I'd suggest making all the trees the same height, and perhaps vary the treeline so it's not a completely straight line.
I have never been a huge fan of the lighting/shade effect, to be honest, only when done tastefully.
In this tutorial, the main image is overlaid with a kind of "light falling" overlay. I think that would suit the current setting you have, because overlays such as the one you're using tend to obscure important details rather than make it more atmospheric like it aims to.
@Erojiji Bloody fantastic. I'd like to see how a character looks running around in it, since that's what's usually the problem with parallax maps, is that the character becomes too detached from the background it seems to be running on.