I get what you're going for with perspective and the sense of isolation and I think you got the isolation part really well. Right now, option 006 is my fave, but I was wondering if you could raise your point of perspective a few degrees. Not as much as in 002 or 003, but not as flat as 001 and 006. In the flat view, the elements seem to crowd into each other. Using your astronaut in 006 as a reference point, it looks like you're seeing it from the level of another astronaut that is standing several meters (or feet) behind and to the side. By bringing the elevation up, as though from a drone, you could still get the amazing background, but start to see the separate structures. Maybe I'm just getting carried away by minutiae. In the end it's a splash screen, not an element that's going to remain on the screen indefinitely (unless you incorporate it into a screen background for the tile map, at which point you wouldn't see much). Keeping that in mind, all of what you've presented would work imminently well.