The game is fun, and probably more realistic than some previous racers. You should notice that these tracks are based on actual GT tracks in the U.S. So, in a way, this game can get very repetitive because of its realism, since there is one objective, to go in the same oval over and over again, for laps upon laps...
As with most games of the same genre, there is a Career mode. This one is a little bit more interesting than the norm, though. As normal, you can join a team and go from there. What I liked in particular is the way this was done. At the beginning you are given the option to choose one of the two available teams, after which you have to impress the team managers by finishing a few test laps before a given time. If he's happy with it, you're on the team. Once in, you can earn tracks and cars as reward for your achievements, which can then be used in the single race mode if desired.
Another neat feature is the emotion system the developers tried to implement into the races. Essentially, this is a caution meter for each car in an eye's distance which tells you how aggressive, afraid, headstrong, etc. an opponent is. This should affect your techniques of passing them. I really didn't use it all that much, but the feature is there, and it does what it intends.