Crystal Dynamics decided to put together an 11 minute video on the "Monastery Escape". Before starting up that video, keep in mind, this will spoil your experience a tid bit. Anyway, Noah Hughes, the Creative Director at Crystal Dynamics commentates over the video giving you an idea of everything going on and discussing features.
Something neat in the video that you come across on multiple occasions is being able to eavesdrop on stuff going on either in the background or in an area coming up. You might be traversing past an area and hear above you or on the other side of a wall a conversation going on. You may hear enemies having a conversation before they're aware of your presence. Everything actually provides a little backstory other than be pointless chatter.