Caverns of the Drow is a mini RPG(1-2 hrs gamplay) that utilizes a raycasting engine based off the book Gardens of Imagination by Christopher Lampton, it's difficult to find but try to get a copy of it anyway.

Story:
    You are stuck in the lair of the drow and you must find your way out. You were imprisoned by the drow    but have been recently released. Your dark, perilous journey begins -- you have no friends, no map,        and no food, good luck.

Download

Source

Engine Features:
    Textured walls, floors, lighting, sprites, movable doors.

Please send comments/bugs to me! I've never received any feedback on this game, so I guess it must suck really bad or something. (roman_death at excite.com)