What if instead of crashing on a deserted world you're trying to escape a doomed one? You are the survivors after a massive global catastrophe which leveled almost all buildings, making metal plentiful as scrap but debris is everywhere too. There could be a limited number of days before total cataclysm and you have to build a shuttle before that happens. Instead of travelers passing through you deal with other survivors trying to find a way off, and they may or may not think you can succeed. Raiders still show up (though a story with no raiders using this plot would be cool too) trying to loot the dying planet. As the time draws near, fires and thunderstorms and dust clouds that end all solar generation become more common, and geysers begin erupting lava.
So... the same as we have but with different words... why?
Currently you're just trying to get off a world you're marooned on. Sort of a castaway feel. I'm talking an urgent need to get off because the world is literally falling apart around you, with increasing natural disasters until everything blows up. Same game mechanics (obviously, it's a suggestion for an existing game) just a different storyline that would yield different playstyles. Also, this would take place on a once populated world, which would mean ruins of cities around you and possibly areas with nuclear fallout.
The same game with few different words would yield different playstyles... how?
And once again - why? This seems like a task for the future modders rather than a reasonable idea.
Don't forget this would also impose a time limit to your play time. I've got a few colonies that, so far, won't ever be overrun. But suddenly it is done because of a time limit? No thanks.
I won't even play Fallout 1 without the time extension.
I'd say the time limit would not be the problem, the fires/earthquakes/dust clouds would. It's an idea, might make a cool mod someday.