You'll probably find the latter portion of the campaign a bit tedious; you'll likely have picked out your few favorite mission styles and played them to death by the latter stages of the game, but the reputation meter must be filled. Expect on 20 to 25 hours of story-based gameplay, even after the thrill is gone.
Once you've completed the story, however, Saints Row offers several multiplayer modes for up to 12 players. Sadly, however, the potential for open-world multiplayer action goes largely unfulfilled, as most of the modes pit the teams against each other on small, custom maps that give you no opportunity to run free in Stilwater. Only "Blinged Out Ride," in which your team attempts to collect money in order to upgrade and transport its car around the map before the opposition does, even lets a handful of players pile into a car and go to war with human enemies.