I bought it the other day and I'm just now starting to get deep into the game. It has lots of cars (not licensed cars, but you can tell pretty much what they are modeled after), lots of courses, and tons of circuits. To top all of this off, it also has a robust online league mode where you race for times in a single lap on a course and try to place ahead of other people that are in the league. You can do as many laps as you want, but the league only allows that track to be raced for 5 minutes...so you need to get done before that 5 minutes is up, or you won't be counted for that race.
I raced in my first league today and won by a pretty good margin. The other couple of people in the league weren't doing very well at all, so I'm guessing they were really new to the game, or maybe just not gamers at all.
It's also pretty cool because after you finish a race, you can upload it to YouTube for everyone to watch. Here's my best race, and this one was pretty good except for one small moment where I go off the track.
Check it out!!