for this project im using the sphero bolt. The sphero bolt is a ball that ho can control using a joystick or you can code it. The sphero bolt is faster than the sphero mini and the bb 8 which are also controlled by a joystick or by coding it. Me and my friends were planning to make an arena and then code them or control them to play tag. They would turn red and make a noise when they were taged by another sphero.