I'm usually too lazy to make edits on these sorts of largish pieces, so forgive me if you end up not understanding something, because I probably won't make an edit to show you.
First off the light source seems pretty inconsistent. If the light's coming from the back, as the largest boulder portrays, why aren't the boulders casting significant shadows like the sword (or is that just a crack)? Or why does the tree trunk seem to be shaded from the front rather than the back? And why does the smaller boulder seem to be lit from the opposite direction as the larger one?
If it's coming from the front, the tree trunk's at least consistent. But everything else I listed also applies here.
The grass also seems to be wind-blown, or something along those lines. I've never seen grass growing so diagonally. I'm thinking the direction of the blades should be more varied if not stick up a good deal more.