Those pale atmospheric greens against the sky backdrop are wonderful - I'm also a sucker for blues, greens, and teals, so I'm all over this baby.
What is this Mythos: Actaeon?
And a critique, but on a concept drawing? What to say... Right in the middle of the drawing, between those two trees, your brush strokes look much more rough and hard-edged than the rest of the piece. Has a decent amount of contrast compared to the rest of the brush-against-sky line, so it sticks out. Really, though, it's a concept drawing and I think you were perfectly successful in your mission to explore shapes, colors, etc XP I wouldn't worry.
Mythos is (or, will be, I hope) a series of animated shorts telling various Greek myths. I'm working with a friend of mine, on it--she'll be writing, I'll be arting. Hopefully we'll keep each one to around 3-5 minutes (more will be too much for just me!). We're starting with the myth of Artemis and Actaeon.
As to the brush strokes....I started with a custom brush that provided the right tones but I didn't care for the shapes it made. Bleh. I do however like how the brush strokes came out on the grass. I'll see if I can achieve a more natural painted feel in my next one. You're totally right though. Thanks!