Legend of Grimrock

Legend of Grimrock hearkens back to classic dungeon crawl Apple II games - consider it the spiritual descendant of Wizardry, or the dungeons of Ultima and Bards Tale.

You play as a party for 4 convicts thrown into a dungeon that will serve as either your tomb or trials for your absolution.  Since it's not turn based, you are able to get away with slight cheats you would not be able to otherwise.  One such strategy would be strafing around a 2x2 grid attacking and retreating before the creature strikes back.

Much of the game appears to be governed by Zelda-ish type puzzles; find the way to open a gate, locate the key, trigger pressure plates in a certain order, etc.  This is what stopped me playing after 5 hours, there were far too many instances where I was looking for the hidden buttons or trying to figure out what door opened up when I triggered a lever - if it were a roguelike, I would probably still be in the depths.

When resting on levels, you occasionally are visited by a voice that hints at a greater story - all I really got out of it for as much as I played was "find me at the bottom of this place".

There is a development kit as well, and you are able to create your own adventures and a sizeable fan base building them.  This could be a great toolkit to realize some of the classic D&D modules.