actually the premise is pretty unoriginal and cliched by now, it's generally used by people who just want to get into showing off / practicing their sci-fi creative writing skills or just to getting to gameplay as fast as possible with minimal set up needed because basically everyone understands "oh right aliens" the moment they see the basic elements even if they don't read, watch, or play sci-fi stuff.

So there's more than enough stuff about that if you find that sort of thing particularly gripping