Actually it's the game Giants: Citizen Kabuto. The game runs in full screen mode, and there is no way to switch to another application while the game is running. The game does not allow you to save your current status. Command-H does not hide the game. Command-tab does not cycle between open applications. The game has hijacked the keyboard. It also changes the screen resolution and mouse speed, and this may be part of the problem.
Does anyone know of a way to leave an application that has taken over the screen and keyboard without quitting the application?