A great role-playing game for the Intellivision that, while not officially licensed as Dungeons & Dragons, was certainly inspired by it.
Tower of Doom allowed you to start off as one of many different classes, each with its own starting equipment. Some were easier, like the knight, while others were very difficult, like the waif. You also selected the quest you wanted to go on (choice of 7), which varied in difficulty/length.
A map was drawn out in real time as you explored, implementing a fog-of-war like mechanic. Monsters and items were displayed on the map, and when you encountered a monster it moved to a real-time combat screen where you could engage or retreat.
Your character didn't really "level up" per se as collect equipment that improved their combat abilities. You could also pick up potions, which typically had unknown effects the first time you tried them. Some were positiive and others were negative.
Overall not the most advanced graphics of the day, but an incredible RPG entry of the era with tons of replayability and lots of challenge.