Building robots can be a great educational experience. We have already covered plenty of cool DIY robots here in the past. This Desktop RoboTurret from Robot Geek is also fun to build. It automatically tracks down and fires upon enemies. You are going to need a Pixy camera module, a RobotGeek pan/tilt base, a foam dart gun, and a Geekduino to get started.
You can find the instructions for this project here. What do you think? How would you improve this?