It’s awesome. The end.
…
No, just kidding. I mean, yes, it is awesome, but I’m not going to just leave it at that. STO is a fantastic game so far; of course, it’s still in beta, so they’re ironing out some kinks, but that sort of thing can be very easily forgiven. The game takes place in the original or “pure” Trek universe, as I like to call it, 20 years after the events that led to Spock being thrown back in time and creating the parallel universe occupied by JJ Abrams and other beat-boxing directors (The “countdown” events take place approximately8 years and one month after Nemesis, so STO is 28 years later, give or take a few months).
The universe, as the story goes, is pretty much in chaos. Romulus was destroyed, which means that billions of their people died; not to mention that the Cardassion Union is a big fat mess — and to top things off, the Borg have returned, right in the middle of a war between the Federation and the Klingons.
I don’t know about you, but that sounds like a pretty good set-up story to me.

