To be honest going from top to bottom I was extremely disoriented. The foreground and middle ground doesn't follow perspective at all. In fact there are 2 horizons in this pic, but they aren't used effectively at all. The rock textures are random and ambiguous about the lighting, there just isn't enough information present for the viewer to know where the cliffs are in space. Some of the formations on the right side don't even make sense. The creature is the best part of this, but he isn't even affected by the light such as the cliff behind him. Every off-screen decision you make with lighting has to make sense, because the viewer can't see outside of the picture. If you don't want the creature lit, you need to indicate something that is blocking him from being lit.
Also, if you are going to post a series of work, USE THE SAME THREAD PLEASE!
The places in the matte painting where a couple of the waterfalls originate are kind of mysterious, like in nVidia's Cascades demo for DX 10 where the water seems to come directly out of the rock or simply materializes at the rock surface. With the body of rock on the right hand side of the image the edge is not adequately defined in the sense that it's hard to tell which piece of rock is in the foreground and which is in the background. The picture would actually work better as two separate images--one of the top and one of the bottom. Most of the confusing, visually ambiguous part is in the middle third of the painting so I say just get rid of that and break it into two separate paintings.
I love the creature. Is that chemically based bioluminescence or something else that creates the glow from its eyes/head? It reminds me of a background image from Peter Jackson's King Kong where a ceratopsian dinosaur is seen at the base of a waterfall. Portions of the image don't have the same focus as the surrounding rock (in the upper part of the painting) so are not quite photo realistic enough for a matte painting. Dylan Cole could do better, but I doubt I could do anything nearly this good without a lot of practice. My art is in kind of a fallow period right now.
The bottom speed paint works great as a piece of concept art. It has the same unfinished look you find in a lot of digital concept art by the best people in the field.
my crit is kinda similar to your last post.
your overloading your pictures with too much textures and details, its very hard for the eye to go through the enviroment and focus on things.
your technical capable of putting good work out but i think you should think/read more about the design aspect of things.
how to mark things on the canvas to make it read better.
maybe look into old black and white photographs of enviroments, look into paintings of people like caspar david friedrich.
hope this was helpfull