First off, Street Supremacy is basically a racing game with bits of strategy game thrown in. There's a time attack mode thrown in as an afterthought, and a team battle mode where you'll spend most of your time. After choosing a team to support, you'll battle through opposing teams and your own racing mates, eventually gaining control of the streets of Tokyo. To sum up the strategy elements of this mode, you'll pick what areas to move into while your team conducts automated battles that you can't view. You can only see their aftermath on the city map. The rest of the time, you'll have access to the shop, garage, and races, all to earn money, defeat your enemies, and tweak your ride. Then you race. Simple, right?
In terms of gameplay, there is one single element that I liked. Instead of racing to a specific point, playing eliminator, or some other traditional system, you simply need to out distance your opponent. Every car has a damage meter that grows smaller the further ahead of the car you speed. Still, that didn't prevent the poor gameplay, I'll explain. Tricking out your ride literally involves buying progressively better equipment. Don't think that you can mix and match parts for a custom ride that's still high quality, think instead that you have Engine 1 to Engine 7. Get to Engine 7, and you go faster, and that's it. In the end, this means that there's no skill involved. If you can't outdistance your opponent, you lose. That's it.
Graphically, this game is stunted, even for a low quality PSP title. What promises to be a 'race through Tokyo's traffic-filled streets'? is actually a race down a featureless gray highway that can barely manage to put two cars on your screen at once, one of them being your opponent. I can only paint the aural aspect of the game as bland and nonexistent, much like the visuals.
Ultimately, there's nothing here worth playing. Pass it by and stick with one of the few really good PSP titles.