Tower Invaders

Tower Invaders is a twist on the classic Tower Defence-style game.  In Tower Invaders, you must create towers along the bottom of the screen, which will try and shoot down the rapidly descending invaders.  

Different types of tower are available, including pulse laser and zappers, but there are also different types of Invader trying to destroy your towers.  You must destroy them all before they reach the bottom to proceed to the next level, where more and harder invaders are waiting!