That's pretty much how my games for score go, I just haven't been able to get a million points out of one....yet.
It's dreadful work without any margin for "fun" like leaving a particularly furry minor race alive. You need their capital. And their econ capital. (which tech you just happened
to drop at their doorstep, gift wrap and all)
I'm currently dragging my feet through another game but pressing that turn button is starting to take an act of will because I know that only more work is waiting on the other side. =P
Can be done? It has. Is it worth the effort...? It's your time. Oh, I'm not trying to discourage you or anything like that. If you have the required degree of stubbornness, nothing anyone could do or say would. =P