The document discusses using mobile augmented reality (AR) games to foster informal learning in real-world spaces. It describes how AR games can create "bridges" between visitors and places by overlaying digital information and gameplay. The author provides examples of an environmental detective AR game used with MIT students and high school students. For the MIT students, the game exhibited some elements of gaminess like interesting decisions, but lacked clear goals and feedback. For the high school students, the game was more focused on completion than problem-solving. The author advocates designing AR games that balance structured learning and open-ended play to cultivate both fun and deeper understanding.