I think the clouds are a little too white. They immediately draw the eye and become focal points when they're intended to be secondary to the other awesome elements of this illustration. I'd suggest making the clouds a lighter shade of the background tee green color...that way they'll still read as clouds, yet be less obtrusive. Excellent illustration...I love the complexity of the bug-people and the tree's roots and branches. The repeating patternish things that make up the ground are well used and visually interesting. Great work.