When Shadow Company and Inner Circle are fighting, some German shepherds are released. Sometimes they attack the player and the only way to escape is to shoot it or break it's neck.
during the campaign, a nuclear explosion is set off in space to serve as an emp. nukes are also an unlockable killstreak in the multiplayer, and can be set off if a player reaches 25 kills without any deaths.
In the campaign, one of the missions takes place in an oil rig. In the opening to this mission you take out two guards on the lowest floor by pulling them down and drowning them.