I do have a theme called “Offworld Colonies” that is in the early stages. It won’t be ready for some time, though. It will have more space themed stuff. As for robots, that is a good idea. I have given some thought to making a robot pack for this theme and probably will in the future. Retro Cybercity does have robots, it’s just that what you’re seeing for the most part aren’t robots but androids. An example of a robot in the theme would be the serving robots in the “Vendors” tileset.
Keep an eye on my stuff. Because of your interest, I’ll try to do some of these things sooner rather than later if possible.