Well, of course it's the same story. It's a continuation of what happened in the first one. That's like saying Mass Effect 2 has the same story as Mass Effect. It kind of does but what were you expecting? Were you thinking it would go from Locusts that used to be Humans to Aliens invading? Why wouldn't it be the same story? Why would they use a different engine? Do developers really have the money to change game engines with every iteration in their franchise? Is it necessary to do so? What were you expecting? Ever think your expectations might have been too high?