King's Quest 3: To Heir Is Human is a fan remake of the classic game from 1986 released by Sierra Online. The fans have remade the game so it works on modern computers, and redone many of the graphics and sound effects to make them more attractive to modern gamers while still maintaining the classic charm of the originals.
King's Quest is one of the original great adventure games and set the stage for many, many games after it. It has many great puzzles, choices, and a spell casting system. The story is still well written and relevant, even after nearly 30 years. The game is really a classic and this remake allows new players to enjoy it without the many compatibility issues that plague the original versions. Besides the new graphics and sounds, there is a point and click interface that makes the game extremely easy to play.
With such a classic game, it's difficult to see much wrong with it. And when fans update the game, adding features and lovingly redoing the graphics for free, you can't do much but start downloading.