Made a start
I've decided on a concept. It will be a peaceful RTS-style game based around building a lunar colony.Resources: water, silica, metal ore, sunlight (for solar power)
Fixed units: habitat, smelter (turns ore into metal and silica into glass), factory, farm, solar panel, hydrolysis plant (to produce oxygen from water), transport tube
Mobile units: worker, rover
I started on the coding last night, and I made a bit of artwork today:
A loon (any resemblance to a Kerbal is entirely coincidental).