Agent Higgs is a great game (developed by TestTubeGames) that will help students learn about particle physics. Your job is to help keep the elusive Agent Higgs hidden, using a growing knowledge of particle physics. Each level teaches students about a new attribute of atomic particles which will be used in that level. New levels also provide ways to continue using previous lessons.
Click here to play several levels from chapter 1, and here to play several levels from chapter 2.