First off, I love that dino's face and this paint type style you're using. :P
I think that the Cliff Dino's shadow is too harsh compared to the rest of the shadows, which come in a bit more gradually and are not quite as dark.
Having the (screen) left side of the Dino's cheek and the cliff he's leaning on more lit by sunlight would make it so less details are hidden, as well they'd act as nice highlights and would still make the Dino look mysterious.
Another thing is that I think the Dino Rider's hat is too close in colour to the cliff at the top, which makes the hat is making a tangent. Making the top of the cliff slightly darker should fix this though.
Other than that, this is great!
Keep it up my friend. :P