Defender

The player picks up humans, who are in danger from aliens, and brings them to a drop zone for extraction. The enemy landers are attacking them, and will constantly try to pick them up for themselves. Once a human is stolen, the player has a short amount of time to blast the lander and catch the slowly falling human. If the player fails to free the human, they are absorbed into the lander and the lander is transformed into a much more difficult enemy. If the human hits the ground from falling they will die. The enemies are a handful of other alien craft, including some ground units that can turn humans into zombies