The goal was to create a set of secret codes for kids. After the designs complete we had the idea to paint the codes on rocks for the kids to find on their adventure. The kids completed a series of tasks (archery, slingshots, etc) and were rewarded with mysterious notes to decode. They collaborated and in just a few hours had solved all the puzzles. It was great fun and turned out to be a big hit.
Soon after we released some coded messages out to the internet. Over the course of 24k hours we had gotten responses from people all over the world who had solved the messages and wanted more! As rewards we mailed out custom 'super decoder' badges.