New Super Mario Bros. Wii is an entertaining and delightfully difficult game.
As in most Mario games, the story is the typical save the princess routine. Running and jumping through the levels is a joy. The graphics are bright and colorful, not ground breaking, but nice. You will cross a total of eight worlds on your quest to get Princess Peach back. Each is themed. There is a desert world, an ice world, a fire world, and many others. The power-ups that Mario finds on his quest are the typical Mushroom, Fire Flower, and Starman. But this time his arsenal includes the new Propeller Suit and Penguin Suit. Both are useful in their own right. I found the Propeller Suit to be slightly more useful, seeing as it can save you from a bad jump.
The multiplayer is a great addition to a great game. While the single player is certainly fun, the multiplayer adds a whole new element. You can pick up and throw other players. This can lead to a few amusing moments, but you don't want to do this all the time. You could lose friends. The multiplayer is fun, but can be frustrating. You can't take it too seriously.
You might have heard that this is a ridiculously difficult game. Don't worry, those claims are exaggerated. It is hard, and you will die, but if you are used to old school plat forming, you shouldn't have too much trouble getting through the main quest. The real challenge comes from getting all the star coins. Some of the levels are set up to test every skill you have. Even though it is hard, it doesn't feel cheap. This is thanks to the fantastic level design. You always know why you died, and how you could have avoided it.
The music is nothing to boast about. Nothing radically different. Mostly remixed tunes form previous Mario games.
This is ultimately a highly entertaining game. The difficulty is pleasant and never cheap. It could have benefited from better graphics and sound, but this doesn't affect the game play at all. If you have a Wii, this is a must buy.