While the DS also launched with racing games like Ridge Racer DS, it can't, and shouldn't, rely on hyper-realistic graphics. Without state-of-the-art graphics, and with no possibility of a steering wheel attachment, a handheld racing game can't provide the same immersive experience as its console equivalent, and therefore must get by purely on the strength of its racing engine. The "fun factor," as GamePro would say, is the only consideration.
With a few new racing games on the way, it seems like a good time to ask: do you play handheld racing games? Obviously we're not talking about kart racing here, since we get that question answered every Thursday.