I bought this game about four days ago and have played it for about 10 hours. Just the fact that I can play it that much tells me it's a great game, however, in that 10 hours I have only unlocked 8 tracks and 2 cars (and a couple helmets). The game gets ridiculously hard after you get all the silver medals. The graphics are amazing and the courses are a lot of fun, I just wish unlocking new stuff was easier. All in all fun to play for one or multiplayer, very pretty, and...challenging.