One of the best racing simulators around.
You basically get to start out and buy a car like in all Gran Turismos and then get more cars and soup them up. The game is fun and will take you a while if you want to play through everything.
The graphics look really next gen and the cars are amazing looking. The environments look a little better than it did in Gran Turismo 3 but they still do not look that great.
The sound is pretty good and there are some good songs.
One thing I did not like about this game is that when you upgrade your car and if you want to sell the car, the upgrades do not add any value to the car so it will be like buying the car and not upgrading it and selling it.
If you like racing games then you should give Gran Turismo a try.