3. Timers
As a writer, I understand the urgency of a deadline and the imperatives behind quick thought requiring actions. When given a level with a cool feature, such as driving and flying, I would want to take it all in, to admire the pretty skyboxes as they fly by. The shaky camera action that occurs in a lot of timed missions throws off my ability to actually judge the environment and takes me out of the experience. A proposition I have made multiple times is to have one timer across each level with quite a bit of time, to allow the player a more realistic sense of the situation. That way, if you leave something until the last minute, you really get that sense of self, and an impact on the world. Having to transport NPCs as "escort missions" used to be a chore, as the AI was as intuitive as a neo-luddite at E3 but with games like BioShock infinite and The Last of Us leading the way with computerized partners, games have started to add arbitrary timers to these otherwise easy systems. However, a well crafted AI system is the best way to enhance any kind of NPC interaction, timers are not.