A great game. Perhaps the best Sonic game I've played...ever!
Pros:
* Speed - lot's of it
* Graphics - I loved the way this game worked with the graphics. It's very improvised in a good way
* Many levels - It has good replay value
* Good level Design - This is what got the Blue Blur famous
* Challenging - This game ain't no walk in the Park. The Boss Battles put me through some challenge
* Music - The songs are pretty good
Cons:
* Level Design - Sometimes you have to memorize a part of the level to live
* The space between screens - There is a short time where you can't see Sonic, but this really isn't that big of a problem
Overall, I love Sonic's 3D games, but think this is my fav. I definitely recommend this game to any DS owner. Have fun!