The best Sierra game, period.
Before the big push to make VGA the standard Sierra managed to really squeeze some great looking games out of the old 16 colour EGA card. King's Quest IV and this one being the best of their EGA efforts but beyond nice EGA graphics this game took the already fun Sierra adventure a step further by introducing some RPG elements: combat, character classes and players statistics.
You have the choice of playing three different classes: fighter, magic-user and thief. Each class gave the game enough puzzle differences to make it worth playing over again. The fighter was the most basic of the three, essentially it was like a regular Sierra game with combat added. The magic-user added of course magic, and had the challenge of competing in a tough magic contest later in the game. The thief was my favorite of the three, allowing you to join a thieve's guild ("thou shalt not steal... here") and you could break into homes at night to make some cash. After picking your class you'd assign some points to your attributes and skills, if you wanted to as a thief you had enough points to add the skills of the fighter and m-u and be able to access their parts of the game.
The plot revolved around your character being in an unhappy valley, ruled by the troubled Baron Stefen von Spielberg who not only has his children kidnapped but his court jester is missing too (alas poor Yorick!) all the while the valley is being raided by brigands.
While the game is not very hard it is a ton of fun. There are a lot of quests to do and places to explore with multiple solutions in some cases. The type-in interface is the best it ever was and the Sierra humour is good.
The combat is a little sticky. As its a hybrid, the rpg aspects may not appeal to hardcore adventure gamers and those rpg aspects are too light for dedicated rpg players. I happen to like both genres so its perfect for me.
The Bottom Line
Hero's Quest is definatly the jewel in the crown of the early Sierra adventure before their fateful switch to the mouse and VGA graphics. If there is one Sierra game you should play its this one.