The big twist doesn't even come up until the end. 
  
My main complaint is that it seems as though the ending is completely rushed through. There are also several broken missions that have no ending, and several missions you're assigned that were taken out of the game, which leaves a huge gaping hole. 
  
But I love the game. I've beat it twice, once as a LS Sentinel and once as a DS Sentinel. I have to play it through as a female, too, just to see if there's a big difference in the storyline.