Awesome multiplayer, but lacked on singleplayer.
The graphics could have also been better because if you look at "The Legend of Zelda: Ocarina of Time", or "The Legend of Zelda: Majora's Mask" there graphic level is a much higher.
The game had secrets which I liked, but most of them were too hard to actually accomplish . Like the one at Wario's Stadium, where you could jump over the wall ( or whatever it was supposed to look like) half the time you hit the wall.
They could have worked on this game a bit harder. I believe that Nintendo lost a few of their game players with this.