Here is something I think developers of games that are fueled by storylines need to consider: You introduce the player to some story. You give some characters, some event, maybe you do this so well that the player really wants to unravel the mystery/ find out what happens next. Then you send player on an errand, like player has to travel somewhere, find some clues, fight somebody, whatever. You need to take into account how long these various parts of the quest are going to take the average player. If it takes me 20 minutes to travel to the next part of the quest, then I am given a two part side quest in order to advance the main quest line, which takes another half hour, well by then I don't even remember what I was doing in the first place, and then each time you tack on more and more subplots I start becoming annoyed. So, when you are writing a book or making a movie, you know precisely how long it is going to be before you pick things up, slow things down, make the big reveal, etc. This is hard in a game, and especially an "open world" player freedom type of game. I think if you are making this type of game, and having story driven quest, you need to nix the total player freedom deal and get some control over things so you can deliver an experience that isn't 1. boring, 2. annoying, or 3. frustrating.