It is quite long, which can be a good thing to come back to. But mabye a fast foward button is needed on the maps. It doesnt seem original to me, how many of these types of games have i played now? Which came first? Not bad though..
If i dont know the symbols im aiming for, it kind of just becomes random clicking and hoping. So i dont find it to be a game of skill, or fun...but thats just me.