It's like Mario Kart, but not cartoony. The races are pretty quick and you get actual cars to use. A lot of the power ups are similar to Mario Kart power ups, but the game is at a much faster pace. You rank up as you earn "fans" from each race. As you go up ranks, you unlock more vehicles and mods that you can put on your vehicle. The nice thing is that you can jump in at level 1 and still be able to beat a lvl 35+ person. It doesn't make it impossible or frustrating for people starting out. There is a multiplayer demo on XBL and PSN for the game.
Also, you can get it pretty cheap this week. KMart has it on sale for $40. Activision also has a $20 manufacturer coupon that you can use at KMart as well to get it for $20. Best Buy also has it on sale for $40, but not every Best Buy will let you stack the coupon on top of the sale price.
Here's the link to the coupon if anyone is interested. http://www.blurgamepromotion.com/
It does make you install that coupon printer thing that a lot of online coupons use these days. It will also let you print out 2 of the coupons. They have unique codes on them so you can't photocopy for people.