We were asked to produce a demo that would consist of a series of cups that would model cells in a body. Different types of cells would have different genes turned on, making a healthy human. There is a switch which will turn off some of the genes which only makes a difference in some tissues. The game is then to throw a ping pong ball into the cells which are suffering from the missing gene. If you manage it an led lights up showing that the cell has been 'repaired'.