Nautilus Nimwit Progression

This is a pictorial progression of a painting I did for a co-worker's cartoon that he is going to pitch. I think they have some pretty creative, interesting and well planned out ideas/stories and I was excited by the chance to make one of my favorite kinds of images: the colorful yet monochromatic glowing light source with plenty of darkness and atmosphere.

I'm pretty proud of this one and I think the importance of tinkering and finessing can be seen in the differences between images 3 and 4. Image 3 is basically there in terms of gross detail, shape and lighting, but I don't think everything really begins to become cohesive and easy on the eyes until the final version in image 4.

Tell me what you think!