Xiaolin Showdown's representation of the characters is good enough to make it obvious who is who. Of course, it is pretty hard to mix up the large Clay with the big-headed Omi. But the camera seems to be pulled back just a little too far, allowing everybody to seem just a little too small for my tastes.
One thing to note is that Xiaolin Showdown actually has voiceovers. This is such a rare even in DS games that I thought it was worth mentioning. Not only are there voiceovers in the game, but each of the main heroes and villains are played by the same actors and actresses from the series. This was a nice and surprising bonus.
The game's music seems to come straight out of the show as well. Not only did I hear the theme song, but several other scores that either came from episodes or sounded enough like the series' style to belong there.