To be precise, the space station is the ONLY thing there made completely Pixel by Pixel
The picture is a combination of Pixel Art techniques and Blend Modes, Shape3D and lots of more stuff I can't remember. The asteroids for example came from a few sample forms I repeated dozens of times, then run Polar Inversion and then Stitch
It doesn't really fit with the rules of this thread, I know, but this thread deserved more attention.
Nice tree, by the way. The trunk could use some work though, more shadowing for example.