Summary: First off, this is a racing simulator not a game. If you want a video game action, there are probably better choices out there. But, if you want to experience racing, then this is one of the best if not THE best racing sim out there. You get a bunch of tracks and cars to start out with that you can expand with the hundreds if not thousands of new ones on the internet.
Conclusion: This is the benchmark of racing games on the PC, Sim Bin have proven themselves as capable developers with previous titles, this is the icing on the cake! There are 4 classes of car and a lot of International circuits, the GTR community have produced add-on tracks and car skins which are free downloads. There is changeable weather, night racing, customisable AI and On-line racing.