Ness from Mother 2 is in this game....
that right there makes Super Smash Bros. Brawl one of the best games on the Wii besides the fact that this game is fun, cartoony, and easy to pick up and play.
Super Smash Bros. Brawl is a game I picked up on launch date a couple years back after waiting for so long. This game takes all of your favorite Nintendo and a couple non-Nintendo characters you know (or don't know such as Lucas, Marth, or Mr Game and Watch) and love (or don't such as Olimar) and puts them in to one full-out (...wait for it...) brawl. It has a lengthy, entertaining, and nostalgia filled campaign that will keep children busy for maybe a week depending on what you set the difficulty to. Characters control well having you the ability to use up to four different control methods, so if you don't like how the Wii controller controls, use the Nunchuck. If you don't like using the nunchuck, use the Classic Controller. If you don't like using the Classic Controller, use the Gamecube controller. If you don't like how the Gamecube controller controls, thats a problem. Pick one. So really, the game is controlled however your child wants.
The game doesn't take itself seriously, it never has. So people complaining about "mindless violence", really, thats all Super Smash Bros. Brawl is trying to be. If you don't like it, look at another game. While there is punches, kicks, and more, the only weapon I find "inappropriate" would be Solid Snake's firepower. While it does pay close homage to the game he came from, it can be a little much for the younger ones.
As for inappropriate body parts, people seem to complain about the character "Samus". Samus' "smash move" is a beam wiping out everyone or thing in its way. She then takes the big metal suit off and is now in a super thin.... coating, I guess. I can't describe it. But you can see the character's... you know whats. Not bare skin. Just I guess "poking" out of the suit. No "detail", you know what I mean, just the you know whats through the suit. I can't describe it well. Look it up or something.
There is online. No chat or anything. Its really laggy so I doubt your kid would want to play it anyway.
And finally, depending on the kid, your child may want to play the games some of the characters are from. Besides Solid Snake, none of the games are rated M. Some of the games are easily accessible and some, like my favorite game, Mother 2, aren't.
So whether buying this game for your kids or not depends. Look in to it though. It is one of the best games on the Wii.