Sonar is a game prototype that demonstrates a core mechanic of 'pinging' to sense your surroundings, much like a submarine's sonar or bat's echolocation. The game plays like a simple game of two-person tag, where one player seeks the other until they are caught and the roles switch. The player generally is completely 'blind' to the geometry of the level and the location of the other player unless they use their sonar to emit a dynamic wave. These convincing waves are either radial or directional and bounce off of walls and the opponent thanks to a very cool cellular automata system. Adding a little spice to the gameplay, each player also can use stealth for a short duration to conceal their sillhouette from the opponent's waves. Stealthing makes it much more difficult, but not impossible, to be located when struck by a wave. A stealthing player cannot emit pings themselves, however, and thusly can leave them running blind should they chose to keep moving. The nature of Sonar's gameplay requires each player to be unable to view their opponent's screen, and it is therefore networked for play across two computers. Sonar was a small group project for an AI/Gameplay programming course, and was designed and programmed in about a 5 week period.