Ridge Racer DS is a remake of Ridge Racer 64 with some changes and additions. All the same levels are there, but there are plenty of new cars, including Namco- and Nintendo-themed vehicles. There is also some new music that was not in the N64 version.
The Touch Screen on the Nintendo DS is put to use all throughout the game, including navigation through every menu and even a revolutionary new control where the player steers the steering wheel with the stylus or thumb ring.
Another addition to the game is the use of the Nintendo DS's Wi-Fi capabilities. Using wireless communication, up to 6 players can race against each other. In fact, up to 6 players can play with a Game Card in only one of the systems. The other 5 players don't even need the game. There will be more items, such as cars, available to play with if all of the systems have a Ridge Racer DS Game Card in though. So there is an advantage to having multiple Game Cards.