The idea is to get from one level of space to the next, by breaking the bric walls that obstruct your path. use your mouse to move the launch pad, catching the ball as it falls. There are power-up's that you can take advantage of to get there faster - but watch out, they can both help as well as hinder you. Click the left mouse button to launch the ball and fire your guns.
Shoot 'em ups originated in the arcades with Space Invaders usually being credited with the genre's birth. Position your options in a strategic manor, targeting weak points while keeping your ship safe from danger.