Not the deepest game, but loads of fun
The first possible mistake you could make coming into Saints Row 2 is comparing it to Grand Theft Auto IV. GTAIV took such a huge turn from the 3 series formula that it would actually be easier to compare Saints Row 2 to the 3 series. What Saints Row 2 tries to do is provide a decent plot and jampack tons of things around it. Some might say the plot is crude and not deep at all, and they would be right. However, instead of the story being great, the gameplay is what makes the game.
You start off with a pistol and the location of the nearest gunshop. In order to do missions, you must raise your respect meter by doing one of the many side activities located around the city (which is a good size, it's not incredibly massive, but it fits the game very well). You might be thinking, "Oh God, side missions? Do I really have to?" Now hold on there sonny jim because these aren't your grandpa's side-missions. Saints Row 2 has taken everything you might want to do in a Sandbox game and made it into a side-mission.
Want to play a cop? Side mission Fuzz where you can beat the hell out of assorted criminals including one the greatest gang fights ever known to man (I won't spoil it, youtube Fuzz missions if you really want to find out).
Want to see how much punishment you can take, but don't want to foot the bill? Insurance fraud! One of the staples carried over from the first game. Try throwing yourself in front of speeding cars and rack up one hell of a bill.
And then there's an escort mission, yea escort sucks... until you realize you get bonus points for throwing people off of buildings, into trains, into jet engines, etc.
Which brings me to the physics. If you want the most extremely real physics, get out. In this game you can grab people as shields, and when you're done, toss them literally over 15 feet. At first you would probably feel it is cheesy, but once you get the hang out throwing people and objects like the hulk it grows on you and you feel the need to just toss everything. Hitting people with cars is just as flamboyant as they are punted through the air in a way that would make the Detroit Lion's Punter proud. (ZINGER)
The weapon selection has many selections to choose from for each category. However, if you continue to do sidemissions to their final levels in all scenarios, they give infinite ammo bonuses and unlockable guns, infinite sprint and 4x health etc. So you might find yourself a golden god just destroying everything in your way. At this point you'll realize the game is somewhat easy, but by doing so lets you choose what weapon sets you'd really like to use. Personally instead of the autofire pistols, I like using my dual .44 revolvers.
The customization in this game is amazing as well. The character creation system is extremely detailed. Look online and you'll find plenty of builds for real life people you can create. Or if you want, try creating yourself, or even try creating a monster. You can customize almost all the cars, your cribs, and what your gang members look like (Ninjas anyone?). The amount of customization is incredible.
This game is a hell of a lot of fun. You can spend probably 20 hours alone doing all of the side missions and never touch the story. There's also online play, but I haven't had much experience with it yet, playing mostly the amazing single-player. If you're a more serious minded gamer, this might not appeal to you. But if you're in the neighborhood to just go crazy and all out, this is a good place to start. While there are a lot of "gansta" themes, don't wory the whole game isn't based around that kind of setting. The music is from classical orchaestra to rap to death metal to A-ha. The game reminds me very much of Def Jam: FFNY where you could customize your experience however you wanted if you didn't want to be strictly rap. All in all, at least give it a rent and see how you do. Remember, you're not trying to beat the game, you're trying to enjoy it.