From GameBrew - a wiki dedicated to Video Game Homebrew.
MicroCars DS is a compact car racing game for the NDS with tiny cars that travel a circuit. It is a tribute to car games where you can see the entire circuit, like Badlands.
Download and extract file.
DLDI patch it if needed (if your card does not have auto-patching) and copy it to the root directory of the card.
The goal is to complete 5 laps as soon as possible and beat your opponent.
Play as the red car and the blue car is controlled by AI, Hitting against walls or the slightest fault will slow down the speed and thus cause you to lose the race.
D-Pad - Rotate
A - Accelerate
Start - Restart
Tested on DSTT/TTDS (firmware 1.17).