Best SSX game made thus far, will appeal to even those who hate snowboarding or racing. It's that fun.
There are race, freeestyle and challenge events. The race events make you go against other racers to get finish first. The freestyle events make you try to get as many points as possibly can by doing tricks and getting the highest score. The challenge events set tasks for you that you must accomplish while going down the mountain. They are not nearly as fun as the other two, and that's why I personally never bothered to do them. The race and freestylle events can and will get difficult so you need lots of practice before you can get gold. The challenge is a nice touch, but sometimes it will get very frustrating.
The game is rather short if you don't do the challenges. You will probably finish the race and freestyle events in 3-4 hours. I think that if you are a fan of the SSX series it's a must-buy for you, but for everyone else a rent would be as good.