Mission 1/Baku: a soldier is trapped in the seat of a submerged car. Mission 2/Shanghai: in an elevator. You're in and out fine but I personally have a fear of elevators. Mission 3/South China Sea: the mission is set in a ship so I imagine the air is stuffy, there are no windows, and you have to crawl under things. In the same mission, two sailors are stuck under a grate while water is rising and can't get out. Mission 5/Kunlun Mountains: prison escape could be a little claustrophobic
Mission 1/Baku: a pilot loses control of a helicopter and it crashes. Mission 2/Shanghai: a helicopter crashes towards the end. Mission 3/South China Sea: a jet tumbles off the flight deck into the sea, during the "Get back to the Valkyrie" sequence a jet flies overhead in flames, and you have to shoot helicopters down with a stinger. Mission 4/Singapore: you crash at the end of the mission. Mission 5/Tashgar: take out a helicopter with a stinger/RPG