The cross-hatching shading technique reminds me of the textured paintings I've seen at museums. The overall rough feel is quite intriguing. Neat stuff.

I think that while the work itself is ambitious, it is hard to define some pieces of it. For example the groundwork is really dark on what I assume is to be the planet surface. You've made the shadows the same color as the ground which is making the image lack depth. Try to change those colors and I promise it will be a more effective composition. 

Unfortunately, the planet in the sky does not look round and it spoils the first impression a lot, IMHO.

Though, the colorwork and uverall looks fantastic. Exept for the bottom half, because I failed to define what this construction is.