I'm suprised to be the first to write a review for this game anyway, onto the review.
Ok so if you haven't played any of the previous games (or brawl by now) you most likely live in a cave. This is probably the best wii game out right now. Not much has been done to the gameplay but thats a good thing, because the gameplay is alreay perfect.
So like in any other ssb game you start off with a few characters from all across the nintendo universe. I'll name some the out of the box ones. Pit, Metaknight, Pokemon trainer (he has squirtle, ivysaur, and charizard), Ike and many more.

SPOILER WARNING
Now i will talk about the new and improved adventure mode, some of the other characters, and other unlockables.
The adventure mode is HUGE it took me almost 30 hours to beat it and thats on easy. The main story is all of the charters have to team up to beat all the nintendo bad guys, and some odd shadow things. Near the last level you see ganendorf and you thing "oh he's the one behind all the shadow things", but the you see him later bowing dow to master hand and then you think "well i supose it master hand", BUT THEN you see master hand KILLED by some new guy called Taboo, so yah the story is pretty cool to watch unfold (fanboys eat your heart out).Something else cool about the adventure mode is you can unlock all the characters in it. Some of the other characters you have to unlock are Marth, Lucario, ness, R.O.B., Lugia, toon link (he's the new young link) , Sonic (yes the heghog), and Solid Snake.
Some of the other things to unlock are, Trophies, Stickers, Music from almost every game, and new stages.
Some the other cool things in Brawl is the power to store replays on your wii or sd card, say you just hit 5,000 feet on the homerun contest, but no one was there to see it thats ok save it as a replay and show it to all your friends later. Something else cool is the stage builder, it not my favorite new toy in Brawl but it is a nice addition. Also you can send your custom stages, replays, and photos over wi-fi.
Ever wish that the world could see that photo you took in brawl well now everyday you submit a replay, photo, or custom stage to nintendo and once a day they will send out one of each thing to everyone who gets on wi-fi.
Next is single player, this includes classic mode, adventure mode, all star mode, homerun contest, Mulit-man brawl, target test, boss battle, and events, but I'm not going to go into any of that. Although it is fun for a long time single player can get old, but with all this stuff to do it will keep you happy until you have friends over which is where the best part of brawl comes in.
MUILTYPLAYER
This is a great game to have at a party, and this is where brawl is the best, theres normal brawl which has tons of rules to customization your match, theirs also Tortament, and special brawl.

To sum it all up bralw is a must have for wii owners, i could have gone on for a few more hours, but i'll wont.

I give Super Smash bros. Brawl a 9 1/2 out of 10