With the mouse you have to draw lines between three objects that are of the same kind, and even more
With the mouse you have to draw lines between three objects that are of the same kind, and even more of them if possible, eliminating them and earning points in return, which is what you should be after. Before the time goes out on you completely, make it so that you eliminate as many of the items as possible, and earn yourself a big score, simple as that.