7. Ziggurat
You're the last human on Earth, standing atop a stratosphere-high stone pyramid. With only a laser rifle to fend off endless waves of alien freaks, you must make humanity's last stand and kill as many of them as you possibly can before you fall.
You'll have to make every shot count if you want to kill as many of them as you can. Hold your finger on the screen to steady your aim, and your gun's blast will grow and shrink in power. Hitting enemies in the eyes will cause them to explode, killing all those around them.