Awesome multiplayer! Ok single player...
Gameplay: You can do Co-op which is one person drives and the other throws the stuff, but I recommend you control both characters on each kart. The controls are nice and simple. Racing against 4 people is actually funner than most racing games because you can win not just because you picked the better car. How you win is how you use the items... As a single player game it is decent. When the difficulty is hard obviously but you can unlock some more karts and that is pretty much it. This game will NOT appeal to you if you have no friends. And GameCube does not have online so yeah...you need people over to have fun with this game.
Graphics: The graphics are great especially for the GameCube. And surprisingly they look almost the same as the new game Mario Kart Wii. Even though the new Mario Kart looks a little bit better.
Sound: The music is good, not great. Just good. The sound effects are really good though.
Value, tilt: Well I didn't even buy this game. I traded it for Shrek 2 for the GameCube just a couple of weeks ago and it was an AWESOME deal!! But by now the game should be worth around $5-$20 or even less if you are lucky. But if any idiot tries to sell it to you over $20 do not buy it unless you are absolutly addicted to racing games and you have people over at your house everyday.
Well so this is a great game. And another good reason why you should keep your GameCube! If you have a Wii and you are reading this review do not buy this game and go buy Mario Kart Wii. Because this time you don't need friends over at your house to have fun. Why? It's called wi-fi...