I think it's less like this, and more like:Let's say you spent too much time exploring the map and/or completing GIGs, side quests or random stuff, after 30 hours
1) You have several quest lines, let's imagine Panam, Goro, Rouge and Johnny;
2) You can complete Panam's questline, which will give you some benefits in the final battle, but now you have time to complete either Goro's questline or Rouge and/or Johnny's;
3) If you chose to complete Goro's questline first, you'll have to choose between completing Panam's quest or Johnny's quest - and so on;
4) Last - but not least - none of it prevents you from going around the world, clearing points of interest and completing minor side quests, as the "timer" only counts for "main quests".
I perfectly understand your concerns, because racing against the clock was pretty stressful in Fallout 1 and even more so in Dead Rising, but from what developers have said, it's not that:
The Blood of Dawnwalker Lets Players Use Time as a Currency Over its 30 Day Period
Director Konrad Tomaszkiewicz said that players can even bribe characters with gold to do things so that they can save their own time.
Explanation:






