I've got nothing but love for this racing game.
It sucks you in with the first race, which is just incredibly exciting and straightforward.
The controls are simplified compared to something like Forza 2, but the benefit is that your mind is focused on the race and not struggling with simulation controls on a gamepad.
The cars move and feel fantastic. Each race feels different and it's quite an experience to have a car that can tumble around and flip over!
The damage modeling is insane. What did other devs say about car manufacturers not allowing damage? Clearly, those devs must have been lying....because Codemasters gets away with it, and wonderfully so. Damage is a huge factor in your races. You can get totalled and be removed from the race completely. Your car's performance will suffer with each kind of damage that you can get (engine, steering, suspension, transmission---each part can get damaged pretty severely if you aren't careful).
And it's pretty disheartening to see your shiny, beautiful car reduced to junk after a few bumps here and there. Adds all the more reason to race cleanly if you can :D
This game has even more layers of depth....you can't simply stick any sponsor logo on your car. That's because those sponsors pay you money for winning races, and choosing a good set of sponsors is key to getting money consistently in the game. Other racing games should have done this before...I'm glad that Codemasters figured out the proper way to make sense out of sticking all those logos on your car ;)
Later on you even get a racing team mate, which makes races even more interesting. Your teammate will talk to you every so often and help you out during races, doing blocking for you and letting you pass if the situation calls for it. Overall I like how the atmosphere is established while you're playing the game....it provides a good enough level of immersion even without Forza 2-styled heavy car customization.
I really like Grid. It's fun without being too much like Burnout; it's challenging without being too much like Forza 2, and it's got more personality than Project Gotham Racing 4---which is saying a lot because I initially thought PGR4 was the last racing game with the most 'personality'. Codemasters did a fine job with Grid; I can't wait to get my hands on their next, most important game, for the Xbox 360: