I love your rivers, very nice work. I like the style you are shooting for, but to me, the mountians and forests look to 'fuzzy' ... this might be the shading as HR commented on ... this is probably a user-preference, but I'd like to see the mountians a bit crisper and with a slightly more solid edge to it... and for the forests you might try mixing up several close shades of green darker for the thickest parts to lighter for the thinner parts... just my two or three cents

Did you do the rivers free hand with a tablet or ?? how were those done?