Defender

One more time, you are in charge of the earth protection.
Fight against the aliens and prevent them from picking up the humans roaming the surface to convert them into "mutants".

If you destroy an alien after it have captured a human, you must catch the human and return it to the safety of the surface or it will fall to death.
Be careful, if your speed is to hight, the human will crash on the ground.
When alien carries its victim out of the screen, the humanoid will mutate and join the alien force.
When you hear a human screaming, look at the scanner to find and destroy the "picker".

When the situation seems desesperate, use your bomb to kill all the aliens presents on the screen. Un new bomb is given at the end of each level as a reward, only if they are still humans alive.