This one is a really old racing game but I’ve had lots of fun playing it in the past - Tile Racer - News
Its name is Tile Racer, and you can create your own tracks and share with other people. It’ll probably run even on the weakest systems. More info below:
Minimum: CPU: 1200MHz or higher, 512 MB RAM, 100 MB free disk space, 3D Hardware Accelerator Card: 64 MB.
Recommended: 3D Hardware Accelerator Card: 256 MB.
This game also requires AGEIA Physx to run.
Below is a gameplay from the game: