Hi, I'm a continuity/story freak with games. I played Saints Row 1 just so I would understand what was happening and who everyone was in Saints Row 2, for example (actually liked SR1 a lot, funny enough). I think because I read comic books I have this obsession with continuity, as comics thrive on past stories and the like. I have a problem.
Anyways, in my concern about being able to understand every detail of a story I worry I won't grasp what is going on in my newly downloaded Earth 2150 that I got during the GOG sale because I've never played the earlier game. Are my worries for naught?
Well, Earth 2150 was the first Earth game I heard about. Only later on did I find out about 2140.
But yes, you'll be fine. 2140 is just a war between two factions, 2150 is the result of that war, what with how nukes have knocked the Earth from it's orbit and it is getting gradually closer t the Sun.
All of the backstory is in the manual anyway which you get in PDF if you buy from GOG.