Play through 20 brain-melting levels and produce various accidents killing the bad guys.
Use the mouse to aim and shoot.
Make the kill look like an accident. You can"t kill anyone directly by hitting him with a bullet.
Try to finish the level keeping the shot-count at minimum
A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.