We create environments in two passes.
First we're doing 3d scene with very simple models and basic textures. There is no any shaders or lights. We rendering this. You can do it in every 3d application, for example blender.
Second process is a digital over-painting. Our graphic artist do it's magic using his graphics tablet. It can be done also in every 2d painting program. For example there is free one "Krita 2.7". We wanted to work out "our" style and I think that we did it.
It's too soon for us to release public version of our playable demo. Shadow Of Nebula is still in development. There is a lot of work to do. If you are interested in our game, we invite you to our pages. Of course, any news about Shadow Of Nebula will be posted here as well.