You control the car with the keyboard and can accelerate, brake and turn, while the mouse is used to write messages on the cellphone. These messages are usually short and simple, like 'OMFG' or 'haha' but you only get a maximum of 10 seconds to write them.
The objective is to complete the circuit while getting all the messages on the cellphone in time, and this proves quite difficult to achieve without crashing the car at least a few times.
SMS Racing is a fun and completely unique racing game. While the main goal is still to drive as fast as possible, the difference, with respect to other titles in the genre, is that you also have to be very skilled at using the mouse to send messages while controlling the car.