I feel like this is going to be a pretty pointless review, because I'm pretty much going to be saying the same stuff you'll be reading in every other review of this game. But since it seems so rare that I get to rave about a game, I'm going to go ahead and indulge myself.
Arcade racers are easily one of my top 2 or 3 favorite genres, so I've played a ton of them over the years... and I've got to say that this is probably the best one I've ever played. What exactly is so great about it? Let's go over the list:
1) Awesome visuals: The sense of speed is amazing. Even more amazing, I've yet to detect any slowdown at all, a problem that has plagued many racers of late that try to push the graphics envelope. There's not the intense level of detail that you might see in a game such as NFS:Underground, but with everything moving so fast, you really don't notice.
2) Perfect handling: Doesn't feel too arcade-y, but at the same time, the cars control in a manner that feels totally fair. Different cars handle somewhat differently, but so far none feel too sticky or too slippery.
3) Crash physics: Let's face it... crashing is cool. I can appreciate the sim racer subtleties of holding a line, catching a draft, cutting a corner... but if I'm playing a video game, what I REALLY want to do is nudge my opponent into an el pillar at 150 mph... or ram him off a bridge and send him careening into a sailboat. This is the game that will not only let you do this, but it will also reward you with a slow motion depiction of the destructive mayhem that is taking place. Sparks fly and the cars break apart in a manner that looks pretty convincingly realistic.
4) Gameplay: The game does an excellent job of balancing risk and reward. In order to do well, you need to earn boost; and the way you earn boost is by driving like a maniac. Driving on the wrong side of the road, near misses, catching air, sliding around corners, all fill your boost meter. The big payoff though is by wrecking one of your opponents. It fills your meter and adds extra capacity to it. The downside is that if YOU get wrecked (a likely possibility when you're driving aggressively), your meter loses capacity. It makes the races more dynamic in that you have to balance your need to earn/use boost with your need for self-preservation.
5) AI: Doesn't seem stupid at all. The opponents behave as if they know you're there. They'll drive aggressively, particularly if you've victimized them earlier in the race. They also don't drive with superhuman ability, as if the laws of physics governing your car don't apply to them. I got a little sense that the race mode uses rubber band AI, but it's nothing too blatant, and hasn't detracted from the fun at all.
6) Several game modes: races, time trials, road rage (destroy as many cars as possible), and crash mode (plow through an intersection and try to cause as much dollar damage as possible). They all play differently and switching back and forth between types of events as you progress through the World Tour will keep it fresher even longer. And crash mode, which I initially dimissed as a throw-away add-on, is scarily addictive. Not only do you get the satisfaction of creating and witnessing a fiery 20-odd vehicle pile-up, complete with buses, RVs, oil tankers, etc., it's also satsifying as a puzzle-solving game, in which you try to figure out how to generate more damage in order to meet that level's target.
7) Random cool stuff: Wiping out an opponent in an especially creative way is called a signature takedown, which earns you bonus points and unlocks a snapshot of the destruction in action.
If you've crashed, you can go into slow-mo (think "bullet time") and steer your wreck into the path of an opponent and take him out as well, which preserves the boost you otherwise would have lost in the crash, as well as earning you more takedown points.
Whatever complaints I have are relatively minor. For instance, if you wipe out an opponent in the middle of a difficult driving segment, the slow-mo cutaway can be disorienting and cause you to crash once the game's focus returns to you. Similarly, when resuming after a crash, the game will automatically steer you away from another crash that would happen immediately afterwards; but this sudden unexpected loss of control can cause you to crash anyway. The radio announcer can get very annoying if you're obsessively replaying a level trying to get a gold medal. And the difficulty seems a little unbalanced in spots. In some events I got a gold on the first try pretty easily, but in one of the time trials, I've spent about 2 hours on it and haven't even managed a silver. It's too unforgiving.
There are also some things I would've liked to have seen: the ability to save replays in crash mode... also, the ability to view an accounting of the damage (I can't always tell what the big-ticket items were). Car licenses would've been nice too. Honestly, this is something I never thought I cared about, but as you unlock vehicles with generic names, I've realized that it does detract a bit and makes the unlocks a bit less interesting. An onscreen map would've been nice too... not so much to help navigate (I've had no problems getting lost or driving into walls) but rather to see where your opponents are. Ghost cars in time trial mode would've been nice too, so you'd be able to see exactly what pace you need to maintain to earn a particular medal.
So yeah, it's not as if this game is "perfect"... but it's closer than anything else I've seen in a while.