I have installed Graf but couldn't play with it. Too difficult to guss for me. Any instruction for it?

You just watch the light sequence and copy it each time. It's for 5 year olds.

You watch it.. it'll play 1 color...

you wait for it to finish, then you tap the same color..

it'll play again, that same color and a different one..

you wait for it to finish, then you tap the same colors it plays.

and so on..
It's a memory game.

wel I would say it is nice and probably good for memory. I tried and could go up to 13 round which is not very good. I suggest people report here round they can go and after sometimes we can see imptovements in people's memory and even after a few month we can draw a curve showing memory imptovment trend and we may discover some interesting behaviour of the brain.

Maybe I'll have it log the score for every game so people can look back. BTW, Round 13 is good for me...