Fun Fact: There were two other Willow games produced, one for the arcade and one for home computer. The NES version is generally considered to be the best of the three.
Willow was a tie-in to the 1988 film of the same name that roughly followed the same plot, but expanded on the story with new characters and enemies.
Willow mixed mechanics from several different genres. Story sequences were reminiscent of RPGs like Shadowgate. World navigation and combat felt more like The Legend of Zelda, but Willow also had hit points, learned and used magic spells, and gained experience points and levels as in an RPG. What could have been just a cheap franchise cash-in was actually a very respectable hybrid title that was met positively.