In a dimly lit basement, half a dozen blindfolded players are edging cautiously around the room, crunching over tortilla chips scattered on the floor and occasionally dinging tiny bells suspended from the ceiling. Two of them seem to collide briefly, there's a whisper and then a bloodcurdling scream as one of them 'dies'.
This isn't a scene from Silence of the Lambs but a Mexican game called Sangre y Patatas, or "blood and potatoes", now part of the genesis of a powerful and inventive mobile game played entirely through sound.
Papa Sangre, which was released through the iTunes App Store, is described as "the first binaural real-time, 3D audio engine implemented on a handheld device". Too often the silent partner in film and gaming, Papa Sangre's ambitious horror game shows how sound has the highest fidelity of any gaming experience, the fidelity of your own imagination.
It's also a consuming first-person thriller. Players navigate Papa Sangre's world through five palaces - brass, strings, wind, bone and finally the palace of Papa Sangre himself - each with seven levels and missions to gather musical notes that often nestle just behind a monster. Those monsters, including the much-feared snufflehogs, respond to sound - so if you accidentally crunch through broken bone on the floor of the Palace of Bone, watch your back.
Navigation is through the phone's screen, so tap left and right on the screen to move step by step through the game, and swipe the top of the screen to change direction.
Papa Sangre took 73 weeks to create, with a core staff of five and extended team of 10. They worked with the RNIB and a team of visually impaired testers. While they didn't set out to specifically design a game for the visually impaired, a game that was mechanically accessible for all players was an objective.
For Papa Sangre, the next challenge will be to more fully exploit the sensors on the iPhone including the gyroscope, which would mean players could navigate through real-world movement that might be walking or turning on the spot. New environments could be explored, like an underwater palace or anti-gravity in space.
Click this link to purchase Papa Sangre from the iTunes App Store.