A fun game but definitely better in vs. mode.
The term "New" gets used a lot, but I feel that in this case it really sticks. The reason for me is "New Super Mario Bros." plays the same as the original in the simple design. The graphics are better, the ability to go back on levels that aren't scrolling you to the right, the new mushroom power-ups, the world layout, and a few other designs from previous mario games are all different from the original, but I still felt the throw back influence to the original game.
The multi-player Mario vs. Luigi was I felt simple (but my twin 4 year olds enjoy it). What I really liked were the minigame challenges that you played either as a single or multiplayer. Your given the ability to customize the points you win for each stage you play and the selection rotates between the people playing. So if someone is hosting the game it doesn't mean they select everytime. Or you could just shuffle it and let the game choose for you.
Paying 35 bucks for this game was worth to my family. We definitely have gotten more than our share of usage from it.
NOTE: My scoring is based on my whole families enjoyment of the game as opposed to just myself.