You could also have the player protect the Nokia factories, a la Missile command. Letting through Windows logos will decrease the factory defences; letting through Elop will instantly destroy the factory defences *consisting of Symbian logos ) and letting through a Ballmer will cause immediate game over by blue screen.

Maybe there should also be a way of winning the game; e.g. clobbering enough logos will give you your own missiles to fire at the enemy installations

Love the music..