PlusWave

PlusWave teaches the physics concept of wave interference in an engaging way.  As a scientist on a distant moon, you'll be under pressure to learn wave interference, and decipher the truth hidden in the waves.

PlusWave is completely free to play in any setting. However, for $5, you can download a pdf featuring the unabridged storyline, suggestions for ways to play the game as a group, insight into the development process, and more. And you can download executables for Windows, Mac, and Linux for offline play. All of these are licensed for individual use or may be distributed in an educational setting.