Something I'd like to see in future sandbox RPG games, Fallout and otherwise, is a true sense of urgency. I mean, NPC #34 says "You have to hurry! NPC #12 is going to die if you don't go save them right now!" Player then proceeds to dink around for several hours, travel to a dozen other locations, do a dozen other quests, a week passes in the game then finally the player decides to do the "urgent" quest and somehow, miraculously, NPC #12 is still fine, waiting to be rescued. I'd like to see a true sense of urgency in these types of games, particularly where the main story is concerned. Using Oblivion as an example, if the player were to ignore the main quest line, other towns besides Kvatch should have also been destroyed. The longer the player ignores the main quest, the more towns are destroyed. This by no means would force the player to do the main quest quickly, as certain aspects of the gameplay can only be unlocked by "failing" to complete the quests in a timely manner. Additionally, the quests in the game would all impact each other. Again, using Oblivion as an example, the player rushes through the main quest with true urgency, saves all the towns, great, but in doing so, many side quests are no longer available. They too were time sensitive, the NPC that would have asked you to rescue her husband no longer will because he's already dead. If you took time to rescue him, it's very likely another city was destroyed in the time it took for you track down and eliminate the gang of bandits holding the husband. If you talk to her and don't go get him, she later scorns you for letting him die. If you never even talked to her at all, she just cries around that he is dead and no one did anything to save him. That kind of stuff. It'd make the player have to decide what was worth doing immediately and what could be put off and what would have to be left undone, as it'd be impossible for the player to complete every quest and be a hero for everyone.

The game's storyline would even be affected if the player decided to put it off for very long at all. The longer the player puts it off, the less of a world there is left to save, or the fewer people, or whatever. Put it off too long and the player could fail the main quest altogether, but it wouldn't be a game over, it'd just mean the player failed the main quest, failed to stop the big bad, but he/she can continue to do side quests and explore the world that is ever changing based on what the player did or did not do. Just a few examples of ending narration:

1. Rushed main quest - "The Hero forsook all others, for he understood the importance and urgency of stopping Big Bad. The Hero pursued Big Bad relentlessly, he never slowed down, and in the end, he slew Big Bad at _insert_location_here_, stopping Big Bad before she could wreak the havoc she planned.

2. Did main quest, but took a few breaks from it to do side quests - "The Hero pursued Big Bad, stopping to help people in need as he could. The Hero finally caught Big Bad and slew her at _insert_location_here_, but not before she managed to enact part of her plan. Many lives were lost, but The Hero stopped Big Bad before she could fully carry out her wicked plan."

3. Ignored main quest a lot - "As Big Bad carried out her wicked plans, so many lives were lost. She had won, the land was under her control, and no one could challenge her, or so she thought. A man rose to take vengeance on her, for all she had done. He stormed her stronghold, fought his way past her guards, and in the end, he slew Big Bad and took vengeance for the land. We call him 'The Hero' for slaying Big Bad and freeing the people from her tyranny, but I for one can't help but wonder how things might have been if he had acted sooner. Could he have saved some, or even all if he had simply acted faster, or perhaps he was only able to slay Big Bad because he was fueled by the anguish and rage of all those deaths. I suppose we will never know. All we can do now is mourn our dead and take solace in the fact that Big Bad has been defeated."