Santa was kind enough to bring my daughter Karaoke Revolution, and we've been having a ball with it. But, the microphone looks like it belongs to a 70's cassette recorder. (It's the same style as the Mario Party mics, just black.)
I saw that Konami made a pretty nice looking mic for the PS2, but after Googling the crap out of it I couldn't come up with anything else for the Gamecube.
What makes this game is the new Battle mode. There are now three different types of battles. The first is the original balloon battle. There is also a bomb battle where you have to use strategy and time the bombs you throw.