i'm sorry for the last post. i forgot to critic your original piece. i'll try to be constructive as much as i can (and know)
ok the thing:
*the dithering is very poor, but the pattern you use reminds me sega style, wich is totally ok, at least for me. You can make the colors more contrasted or to go from white to bluish gray, the steps should be visible but not too contrasted.
*outlines. the same fail as many: try to think of the outlines as a tool to say where is the light source. You should desaturate the color near the outlines and lower his lightness until about 33% of his original lighting. Black outlines are good to remark some important sprites on games but not to use them everywhere, if you arent trying to keep that style i'd rather consider to work on that fields better before trying to do anything more complicated.
*grass textureżż?? you are making a static pattern on the grass, as i can see, it looks like a c64 checboard
but not a grass texture. it's more like a field to play cards, you know? it's sure it'll help you reading some tutorials before trying to attempt a complex drawing, although it's good to learning on the fly
good luck.
PS: look for references for grass turf on google
