Speed, great visuals, nailed controls
The game mechanic is interesting, you control the game by holding the wiimote side-way and you use various buttons and some specific gestures to perform tricks. If you knock down other characters you get a speed boost . You also have an hyper mode that increases your speed for a short time. This hyper mode can be stocked up multiple times to achieve even greater speed. If you ram in other characters while in this mode, your car will get even faster, it's very satisfying.
Like Mario Kart, you get different cups that rank from slower to faster. The difference here though is each cups gets more drivers, so it can get very competitive at the end. The game can seem easy on the first cup, but don't let that fool you, you'll get plenty of challenge by the second tournament. You also unlock new characters as you win races. All drivers have different stats and car, but I didn't try other ones as I was quite satisfied with the main racer. The visuals are quite nice as well, instead of just using the movie models, the company went comic style. Tracks environment is varied and beautifull and the special effects suit the game very well. Music fits the game as it should, it's not distractive and set you in the mood of racing, nothing that will get you humming when you're not playing though.
It's best if you play the tutorials to learn all of the controls and the game mechanics. The thing though is that the tutorials are long and tedious and that may turn some people off. It's not pick up and play like Mario Kart, there's many things to learn here. I managed to have a good experience by just doing the basic tutorials, but I imagine the advance ones will give you an edge on other players. Don't worry if you don't remember all of the moves though, the game gives you different tips in between loading times.
As a single player, that game is awesome, it has a great sense of speed, the controls are responsive and it's immersing. My advice is, If you don't have friends around often, get speed racer, you will not be disappointed. It will keep you busy till F-Zero Wii (you know it's coming)