Defenda

Defenda is an early Defender clone, later improved upon by Andes Attack.

You are in your ship out to rescue the humans that are under attack by the aliens. The player patrols the two-way scrolling landscape in his ship, preventing the marauding aliens from abducting the humans. If the aliens manage to get a human to the top of the screen, it mutates into an alien horror that will come after you resulting in a fatal collision if not killed. Each surviving human gives you a bonus at the end of each stage.

You start out with three lives. Each time you get hit by an enemy projectile you lose a live, once all lives are spent the game is over.