There are two known printings of the first edition with some slight differences on the cover, mainly on the spine, one has white text, and the other has black text. One of the two has an additional box on the back of the cover that says "Why This Book is For You - See Page 1".
...The problem took the shape of a 12-foot-long, iridescent, green-scaled, fire-breathing dragon. (3rd Edition)
...Graham looked deep into the glass that told the future. His own face looked back, and on his head was a crown! (1st & 2nd Edition).
Normally he would have welcomed a path of any kind through woods, but this one disquieted him, making him think of a string leading a cat into an ogre's cooking pot. (1st & 2nd Edition)
...She raised her voice in song, and a bridled sea horse suddenly swam up to the king's side. The mermaid then disappeared under the waves. (3rd & 4th Edition)
...Averting my eyes, I quickly showed the mirror to Medusa (1st & 2nd Edition).
...Her scream was as hideous as her face must have been. (3rd & 4th Edition)
...That's when the ancient coffin opened and a figure lurched out at Rosella. (3rd Edition).
...That's when she discovered the little key that had been concealed in the rose's leaves.(1st & 2nd Edition).
...Graham realized that he was caught between a Roc, and a very hard place. (2nd Edition).
...Graham realized that he was caught between a Roc, and a very hard place. (3rd & 4th Edition).
...Flames reflecting in its eyes, the Minotaur roared, charged, and lunged at Alexander. (3rd & 4th Edition).
The Royal family of Daventry (3rd & 4th Edition).
Note:The bridge in the background of the third image is apparently intended to be the 'rope bridge' as seen in KQ2. Although the artist portrayed as more of a stone bridge. In fact looks closer to Old Stone Bridge in KQ1. However it does look like it is crossing a chasm with a mountain behind it. The interpretation of the bridge on the map in first edition by the same artist portrays it to be all wood.
The bird in the 2nd Edition map looks more like the 1-headed eagle than a Roc, and the egg looks like its already cracked. This maybe an interpretation of Graham's rescue from the roc.
The image of Rosella in the tower bedroom (in KQ4) is reused to represent KQ7 in the King's Quest Companion, 4th edition (although it doesn't technically relate to anything in the story).