IGN has reviewed New Super Mario Bros. Wii and while they really like it and state you should buy it, they also note the game is weakened by a number of factors including a lack of innovation and online play. Overall it scored an 8.9.
<blockquote>I really, really like New Super Mario Bros. Wii. I have no qualms with saying this is a far better game than the Nintendo DS version, and it could easily be the finest Super Mario Bros. 2D platformer Nintendo's ever created. You should absolutely get a copy, no question.
But, and it's a big "but," Nintendo did not use this opportunity wisely. For as big a project as this could have been, this game's impact is weakened by many factors. It plays it safe with established gameplay with very little in the way of new innovation. It also lacks online multiplayer in a generation where such a feature is expected.
I had a great time plowing through all eight worlds (and then some), but the nagging feeling of it seeming like a step backwards kept creeping in. As a gamer I love New Super Mario Bros. Wii, but as a critic I just couldn't let the issues slide. </blockquote>
News Source: <a href="http://wii.ign.com/articles/104/1044744p2.html" target="_blank">IGN</a>