Had a game idea for sci-fi where we on Earth perfected terraforming and tossed some people up on our moon and mars and mercury.
The moon became kinda entertainment-y. (Come to the moon we've got less gravity! WOO!)
Mercury was a lot harder too do, it was drilled through and the undergrounds the only really habitable places, but still the core of mercury had running water and natural looking places. The only difference was a ceiling all the time... This is because the surface of Mercury is always either too hot or too cold thanks to it's distance form the sun.
Mercury was saved for the labs and brainy areas although still had residential areas.
Mars was the last on the list for terraforming when America decided they had put so much into the moon (which they did) that they claimed it as American territory and kicked out German and Japanese citizens (due to tensions on earth.) The overlooked fact was that USA does actually have the right to do this as the deal everyone made when the biggest and brightest got to work on habitable other worlds was that whoever dumped the most resources into it would be allowed full ownership, but for the longest time that was overlooked for peace. So well within their right they removed all Germans and Japanese which caused things on Earth to get a lot worse and the story eventually breaks down from there for a large scale world(s) war (again).
Anyway that's basically the jist of it except there's also a Mars based Peace Organization goes into killing army leaders so that the war will end and Mars can finally be terraformed.
I ditched this idea for one I like better (not saying it IS better I just like it more)
So if you(by "you" I mean "anyone") wants to use this feel free.