Flashlight tag is a fun game. But I always love trying out new variations on old classics. So I decided to add some simple light sensing circuits to the game to see what would happen. With this circuit, any time that you shine a light on the badge, it beeps for a few seconds. That way there is no ambiguity as to whether or not someone was tagged. It's a fairly simple design that can be built for about $5 each. It probably won't be the next big thing, but it was a fun little project to make.
For step by step instructions for this project, check out my Instructables page: http://www.instructables.com/id/Flashlight-Tag-Light-Sensitive-Badges/