Ridge Racer DS is one of the first Nintendo DS titles and helped served to demonstrate the DS's capabilities.
It is a port of Ridge Racer 64, with some alterations. For example any instance of Reiko Kodama Nagase seen in the N64 version (From the packaging to in-game artwork) is replaced by images of Gina Cavalli from R-Racing Evolution.
In place of an analog stick are three control schemes. Two of them making use of the touch screen.
Easy Play [Pad Control]
Uses the D-Pad for steering and does not use touch control.
Hard Play [Stylus Control]
Depending on where you place the stylus determines the turn radius.
Expert Play [Slide Control]
Using the wrist strap that came with the original Nintendo DS models which has a thumb pad attached, the neutral point is placed depending on where you place the thumb strap. Letting go of the screen allows to re-adjust the neutral point of the touch control steering.
These control schemes are similar to what is seen in Super Mario 64 DS.