A proto-type, not a classic
This is the game that started the ball rolling for the graphic adventure genre. It was the first game to include a controllable third person avatar AND text parser for interacting with the game environment. Bright and colorful, the game chronicles the efforts of Sir Graham to reclaim the three treasures of Daventry and take his place as heir to the throne.
You really can't say anything bad about this game and get away with it. The game is so old, it can't be held to today's standards by any means. That's just the problem with it, though. Some of this game's contemporaries (Zork for one) are still revered and played today. King's Quest is practically unbearable to play anymore -- the characters move excruciatingly slow, the graphics are comical, and the plot/puzzles are not, in all honesty that deep or interesting. The game consists of a conglomeration of fairy tale characters who present puzzles that are mostly easily solved by common sense and folk-lore knowledge.
The Bottom Line
The best thing that can be said for this game is that it paved the way for a classic series and a revered genre. Appreciate it for what its worth, but leave it on the shelf. If you want to re-capture the magic of 25 years ago, download the amazing fan-made remake at agdinteractive.com