FastCrawl

From the website:

FastCrawl is a quick and highly replayable fantasy role-playing game. You control a party of heroes exploring a dungeon on an epic quest. To succeed you must engage in exciting combat against many foes, find powerful items to help you on your quest, avoid fiendish traps, save another champion or two, specialize your characters' abilities as they level, and carefully explore your surroundings... all in as little as thirty minutes.

Every time you play FastCrawl you will have a new game experience as you explore a different dungeon, lead a different party of heroes, face different monsters, and find different treasure. An intelligent game generation system will make sure that no two games are the same.

Play at the level of difficulty and duration of game that you wish; enjoy a leisurely thirty minute break in the game's pleasant environments, or face insurmountable odds in an hour of nail-biting dungeon crawling action. The game is entirely turn based, so it can easily be played in the background and fits perfectly into your day.