The Immortal is a superb game, written for the Megadrive/Genesis as well as possibly other platforms. You take the role of the apprentice of a Wizard who has gone missing in a labyrinth. You enter the labyrinth in a quest to find him. There is some fighting in the game but it is most puzzle solving. It's also genuinely terrifying, with horrible moments galore - like when you're walking along and a giant worm bursts out of the ground and eats you alive. Well, anyway, it's superb, and in my mind, one of the best RPGs available on the Genesis.