Any DS owner should have this.
The Good:
-Fun Levels.
-Cool Power-Ups.
-Fun Multi-player (Mario vs. Luigi, and the Mini-games).
-Sweet Replay Value.
-Awesome extra Mini-Games and it's even more Mini-Games when you play with your friend(s).
-Mushroom House Mini-Games are cool too.
The Bad:
-The game is sort of easy.
-A lot of the Mini-Games are from Super Mario 64 DS.
-You have too unlock World 4 and 7 with Mini-Mario.
To unlock Luigi, just press and hold L and R while choosing a File. You will know you did it right when you here Luigi say his name.