The games that we are currently playing with LocoMatrix require quite a lot of looking at the screen. We have taken care to ensure that maximum contrast even in bright light. Nevertheless, looking at the screen means not looking where you are going, so great care needs to be taken when playing. We have been thinking about games that can be played which use sound (and maybe other phone generated phenomena such as vibration).
My first thoughts on this were musical. Creating a maze where one has to follow a scale of notes. Easiest would be to follow the notes of a major scale octave – but one could be far more demanding by using other scales (minor or modal), chords, or tunes. In the randomly generated grid of numbers above, one would start from the number one, representing the lowest note of the octave and experiment with adjacent cells, until one heard the second, third etc. notes of the scale – one might then have to run through the whole sequence to “win” the game.