Game is mediocre at best.  It' enjoyable for around 10 minutes until you realize the tracks are sloppy and uninspired and the quests are basically the same 5 things over and over again with different racers on different tracks.  There is little to no varience in the drivers (I actually played long enough to unlock them to find out for myself) and nothing worth going through all the cups because you can unlock the tracks without doing that.  The only thing you can unlock is a different coloured drivers liscence?  Oh wow...