THE DARK CRYSTAL / Sierra / Apple II
The Dark Crystal was one of Sierra's earliest adventure games and was programmed by none other than Mr. Al Lowe, who had a bit of a career making children's games before moving on to develop the Leisure Suit Larry series and Freddy Pharkas. The Dark Crystal will drive both children and adults up the wall with bad/primitive design choices, however; in spite of a very small overall game world, missable items and the lack of a save feature will force players to replay the same bits over and over and over and over and over.
It follows the plot of the Jim Henson movie that I somehow managed to never see despite being a kid in the 80s. While the graphics look simple and jaggy (and each screen has to be slowly redrawn every time you do something or move), this was actually a pretty big step forward for the genre as a whole - it actually looks a heck of a lot better than Sierra's prior efforts.
The graphics apparently came at the expense of programming finesse, however. When the size of the current text box exceeds its little space underneath the static graphic screen, the game simply wipes the graphics out and fills the screen with text abruptly instead. The parser is also very limited, even for 1984; you can't get an "exits" summary and most attempts at action are met with "I don't know how to X." Infocom's text adventures were leaps and bounds more sophisticated at this point ... but of course no graphics.
The game was also released in a "kid's version" called Gelfling Adventure; it replaces the parser with simplified menus and in doing so actually makes the game a hell of a lot more playable. It also tones the text down for kids, however, removing a bit of the detail and exposition and language that gives the game a darker edge. I'd still take it over this version, though, if you just want to cruise through the game as a curiosity and see what "cutting edge PC gaming" looked like in mid-1984.