I hope Project Eternity features some nice riddles like the Baldurs Gate series did.
Little ones like "I have two heads but one body. The more I stand still, the faster I run" and big ones which involve quite an amount of thinking.
They can be integrated in various ways into the game. A chest containing an Elvish sword of great antiquity which can only be opened by solving the riddle on the paper you found in the desk or an statue which guards the entrance to an mysterious cave.
Off course difficult riddles shouldn't hinder the game progress but maybe open up some fascinating side quests if solved.
What do you think?