Modern Warfare 2's campaign is the perfect length, actually. Call of Duty: Modern Warfare 2's campaign is a brisk five-and-a-half-hours. I was sightseeing on that playthrough, too, because the game is gorgeous.
The Modern Warfare 2 campaign has 17 missions, and as with previous Call of Duty campaigns, the action is split across various continents and gameplay types as it jumps between the perspectives of multiple characters.