Real racing, Real Physics, Real sensations, Real Opponents - If you haven't got a wheel, don't bother applying.
The three developers of this game are releasing it in stages - S1 and S2 have been released, at a cost of £12 (UK) per stage. This is a review of the game as it stands at the time of writing - S2-release, patch 'P'.
This is called the 'online racing simulator', and it really does come into its own online. Thanks to an easy-to-use online server finding system, similar to that in use with that used in the likes of Half Life 2, you can find a track that's racing the vehicles you like to race. Of course, being online, you occasionally get some who don't know how to drive, but on the whole the standard of driving is excellent. You can choose to join racing teams (I'm a member of the GURU racing team, username LazerFX), and gain them prestige with your racing abilities.
So that's who you can play against... but how does this game actually play? Well, if you've ever driven a car in anger, you'll be right at home. If not, know that you're the closest most people ever will get... the physics are excellent, and are being refined all the time. In Patch 1, there was some discussion about suspension types, and the sort of differential used - the developers listened to the discussion, and refined the physics, giving different differentials and more advanced suspension.
You can tweak the settings to an outstanding degree - it's more like an advanced F1 simulation (Like Geoff Crammonds exellent Formula 1 Grand Prix series) than a GT or road car racing simulator. Everything is there, and you can change it - sometimes with detrimental effects, sometimes with excellent effects.
So, what does all this mean when you actually play the game? It means you get a responsive, fun, exciting and rewarding racing game, that takes dedication to get the best out of, but rewards you highly when you do - pulling off a time that's just 1 second off the current world record feels like you've just won a prize...
Now, for the down sides - the graphics are OK, but nothing special. You can modify the graphics and logos of the cars, and thanks to an online image-hosting system including with the game, you can share this modification with everyone else playing (Provided it follows certain decency rules, etc.). However, the graphics are good enough that, while they don't knock your socks off, they don't detract from the gameplay.
The sound... well, the developers have gone the simulation route with the sound. It's supposed to actually reproduce what the engine is doing, complete with exhaust sound simulation. Sometimes, it's brilliant. Other times, it's terrible - V8 performance 'formula' cars that sound like mopeds... Nice, but not quite what you expect from this sort of game. However, it has advanced a lot since the S1 days, and it's going to get better still - continual development is the name of this game...
Overall - a difficult, but rewarding racing game that will just keep you coming back with its amazing physics, and fantastic gameplay. The updates really mean something, and the development team cares about its public. Revolutionary? Definitely.