I finally got back to more CoD4 today and completed the first act (which actually puts me halfway through already, going by mission number counts alone). The high point of this one was definitely a part where you take the role of an AC-130 camera operator, calling down weapons fire onto the ground below as you watch on an infrared camera as the squad you’re protecting moves forward. It plays out a lot like this real video of an AC-130 attack, and creates an odd feeling of detachment from the actual combat.
The end of the act is another unexpected atmospheric bit that sets a mood really well, but I’d better not spoil it…