Take a match 3 game like bejewelled or candy crush and modify it for blind accessibility. If you did it tactile you would be gaining research on an accessible tactile interface for everyone. If you did it audio you would be creating an accesible musical interface.
Each match 3 could be an inversion of a chord. Colors could be represented by instrument, pitch and tone could be up and down, left and right.
I might be wrong about this but it seems to me like each step in a match 3 game is like exchanging two faces of a tetrahedron. Doesnt that make solving a match 3 game like doing fluid dynamics step by step? If not, then maybe that's another idea, to make a tetrahedral space-filling puzzle either in 2d visual, tactile or audio display.-- JesusHChrist, Jun 13 2013random, halfbakery