It's easy to get distracted in Saints Row 2. The main story is actually pretty interesting. The notorious Boss of the Third Street Saints was nearly assassinated in a boat explosion and has been languishing, comatose, in a prison hospital for years, but they unexpectedly recover and make a daring escape, only to find that their once fearsome gang has completely fallen into ruin and their nigh-unstoppable lieutenant, Johnny Gat, is about to be sentenced to death for committing over three-hundred first degree murders (and one case of attempted murder). The job, then, is to rebuild from the ground up, taking out three whimsically-themed gangs alongside a colorful crew of low-lifes and thugs. It's over-the-top and implausible, but there are a lot of gun-fights and car chases and funny, morally bankrupt conversations along the way.
However, to advance the story, you have to earn "respect" and the only way to do that is by completing side-missions. These side-missions are usually introduced by amusing cutscenes that flesh out the gloriously amoral world of Stillwater (for example, the doctor who wants to prove women are just as good at medicine as men by setting a new record for most surgeries performed, but doesn't actually want to do the work and so hires you to commit massive amounts of insurance fraud). And, often as not, the activities are just as compelling as those of the main story (the insurance fraud, in particular, is a hoot because you have to throw yourself in front of cars and try and ragdoll as long as possible, which, you know, is absolutely nuts). So it happens that with more than two hours in the game, I've probably only played about a half hour of the main story.
Overall, from a perspective of evaluating Saints Row 2 as a game, this is a virtue. Stillwater is a huge open world with a lot to do. And compared to something like Skyrim, these side activities are more diverse and engaging (as great as Skyrim is at a game, virtually all of its sidequests were of the "go to place, kill monsters, grab macguffin" variety). Yet I have a deadline here. Three games to get through, twenty hours each. If I'm being reasonable, I should probably just do the bare minimum of side activities so I can unlock all the story missions and only if there is time left over at the end, should I try and finish all six levels of every diversion.
I probably won't do it that way, though. The diversions are the best part of the game, and if I wind up going past 20 hour so be it (also, I hate leaving a diversion with something like 4 out of 6 levels complete - it just bugs me).