Semitone
About
Semitone was developed as one of a group of quick game prototypes, and was started as an experiment in spatial and binaural audio. You are put in an empty room, with a set of speakers that play a set of sounds, and you must identify the source location of the requested sound. The game also experiments with stencil buffer geometry cutting: the base room itself is entirely made up of a single cube, and the holes in the floor are stencil buffer magic: if you're observant you'll notice the holes are never in the same place.
Headphones recommended!