Just like the TV show, Wacky Races is directed more towards little kids than toward the other ones. Basically, it is another clone of a the classic Mario Kart series.
The graphics are just a bit better than mediocre when compared to most games that came out at the same time. There are also some strange things wrong with the control system. Which is kind of weird because it is basically the same engine of the great Mario Party games. I personally think that the tracks are more challenging that most of the other kart type games out there.
Unless you or your kid is a fan of the show Wacky Racers, and do not have any other Kart game, then there is not too much of a reason to get Wacky Racers. If you can find it for a cheap price and have some money to burn, then you might get want to get it because it is fun, but not for a very long time.