Now I put myself the restriction of not building any spaceport, i.e. I only go for score victory. I disable the other victory types to avoid a situational victory (cultural or militaristic). The end game challenge is high to prevent AI from winning a science victory before the end of the 350 turns, actually much more than the early game.
Has anyone else tried this to keep the end game fun?
Most of all of my games have Science, Culture and Religious victories disabled. Of course, I still try to achieve each but I don't want the game to end before the turn limit is reached. I only leave Domination Victory active as something more concrete to guard against.