Being a fan of the show I was looking forwards to see how this game would compare.
They have done a good job of making episodes, that include the normal colour and character interaction you would expect from the tv show. The stories themselves also fit in well with the style of the TV show, and it is nice how they interlink them.
While they have not got the full cast for voices, they are not bad.
The main issues I have with the game are it is very short - they seem to have written each of the 4 'episodes' to actually take about an hour each to do, so you can finish the game start to finish, including collecting all 1000 points of achievements on the Xbox (the game is very linear you cannot miss any of them in a single playthough), in about 4 hours.
The mini games, while fun, are also extremely easy to do.
Overall the game is a lot of fun and fans of the series will appreciate the writing. Given how short it is though, and there is no re-playability, I would advise waiting until the price drops appropriately.