As the "cat", the player chases somebody through a procedurally generated urban environment. The player is always locked on to the target, and can adjust their aim with the mouse/right analog stick. Of course, the player has to dodge obstacles as well as whatever the "mouse" is throwing at them.
As the "mouse", the player is running away from somebody through the same environment. The difference here is that the player needs to get to a designated location. In order to lose your purseuer, you can shoot at things to create obstacles, take tight turns, go in unexpected directions, etc.
No matter who the player plays as, the game is about speed and quick reflexes.