Summary: Racing fans, get a PSP. Sure, you won't get all the good games like Brain Age, but man, racing games on the system are just horrible compared to PSP. With no analog stick, good graphics, or enough memory, the DS just does not do racing games well.
Conclusion: I'm probably one of Ridge Racer's most ardent fans but even I failed to squeeze any enjoyment out of this particular game. What makes it so bad is the way the cars handle: Anyone familiar with Ridge Racer on the PSP will know that the cars drift around corners as if they're caught in a centrifuge.