This chapter is the only one in the official King's Quest series where the action takes place during a specific and limited amount of time— the events of the game cover about 24 hours (8:00 A.M. to 8:00 A.M.). In fact the game, much like King's Quest III, had a real time clock and time would pass even if the player wasn't solving puzzles. Some activities must be completed during the day, while other puzzles can only be solved at night, and solving certain puzzles would cause the clock to skip ahead.
King Graham has suffered a heart attack and is on the brink of death. The good fairy Genesta contacts his daughter Rosella through the Magic Mirror and offers her assistance. Genesta then teleports Rosella to the land of Tamir, where she learns of a magical fruit that can heal her father. However, Genesta herself will be unable to teleport the princess back to Daventry, and die if her magical talisman— stolen by the evil Lolotte— is not returned.
Rosella must win Lolotte's trust by performing three tasks for the evil fairy; Rosella must bring a Lolotte a Unicorn, a Magic Hen and Pandora's Box so she may rule the world. Fortunately, Lolotte's son Edgar develops a crush on Rosella and will aid her when Lolotte imprisons her for the wedding. She must then defeat the evil fairy to recover the talisman and return home to Daventry.
It is possible to complete KQIV without retrieving the magical fruit, but failure to do so leads to a tragic ending.
As stated in the game scripts KQ4 is largely a serious game. It has one of the solemn stories in the series and touches on some tough topics. There are puns but they are limited to the deaths only, and even then many of the deaths do not have puns (but are rather melancholy in nature).
AGI and SCiEdit
This game was simultaneously produced and published in the AGI and SCI engines. The AGI engine was used in all earlier Sierra adventure games, the SCI in all later ones. The main advantages of SCI are a higher video resolution (320x200 rather than 160x200 in AGI), sound card support, mouse support, and a more versatile scripting system.
The AGI version was made because Sierra supposed that contemporary low-end systems would be unable to run the SCI version and would require a "lighter" version of the game. However, sales figures proved them wrong and the AGI version was swiftly discontinued. Because of its rarity, the AGI version could be considered a collector's item. The Apple II version had improved sound compared to the PC AGI version
The two games are identical in gameplay, except that the SCI version was updated with some additional or alternate parser responses. However, AGI version 2.0 contains the famous "BEAM ME" easter egg (which transports Rosella to a Star Trek-esque room with the development team present.) This easter egg is neither present in any SCI version nor in AGI version 2.3. There are a few other easter eggs and animations that exist in AGI version that does not appear in the SCI version as well. Such as a squirrel in a tree (not seen in the SCI version). Other differences include a few differences in geography such as extra bushes in a few screens in the AGI version. There is also a hint added to SCI version that will remind observant players to look inside the boat to find the bridle (the narrator will tell the player that she sees a glint coming from the boat). In the AGI version it is very possible to leave the island without noticing the bridle (as there is no given clue using the look command).
As a form of copy protection, a random word from the manual must be entered upon startup. Compilation releases provide a printable file of the possible words.
Behind the scenesEdit
- Assorted cuss words are acknowledged in the parser bringing up a message; "Perhaps you need to purchase a copy of Leisure Suit Larry?"
- Typing "undress" or "remove clothes", will bring up the comment, "Not in front of the game players!"
- Rocking the cradle will cause the cradle to rock for a few moments, and the haunted lullaby to play.
- King's Quest 4 begins directly where KQ3 left off, it repeats the scene of Graham walking to the wall, grabbing his hat and tossing it to his children. It mentions that Alexander had returned to the castle shortly before, after having defeated the dragon and saving Rosella. Unlike the ending of KQ3, Graham doesn't speak to the twins as he tosses the hat. This is mentioned in the introductory text in the manual as well; "According to legend, shortly after Rosella's rescue King Graham decided it was time to pass on his adventurer's cap. Gathering in his wife and two children, the King offered a grateful smile upwards, for each member of his family had given him great pride. Gazing down at his children, he couldn't help but see the glint of spirited valor in their eyes. Knowing the future of his kingdom would rest soundly in the hands of its future heir, he slowly lifted his hands to display the infamous adventurer's cap."
- Also a trivial continuity error is where the cap is when Graham picks it up. At the end of King's Quest III, the cap is hanging on the wall. At the beginning of King's Quest IV, it is on a table next to the throne. This table is also not seen in the throne room at the end of KQ3.
Since the gaming industry was dominated almost exclusively by male players, Roberta chose to take a risk of releasing this game with a female character, fearing it would get criticized, but also hoping it would draw more women into gaming. This was apparently a success as the game was released to critical acclaim, and had more female players than previous games. It became the most successful game product of the year. However, at the time Roberta said that since many girls and women were already avid King's Quest players, replacing the hero with a heroine "felt natural, like it was time." 
- I knew the female lead is just fine for women and girls who play the game, but wasn't sure how it would go over with some of the men. And you know what? It wasn't as controversial as I expected. However, it was real strange at first designing the game; quite a different point of view. Having the women die bothered me more than I expected."
The game received Software Publishers' Associatin's "Beast Adventure Game" award in 1989.
- ↑ Narrator (KQ4SCI): This is not a humorous game, Rosella!
- ↑ Narrator (KQ4): "With the return of his long-lost son, Alexander, and the rescue of his daughter, Rosella, from the terrible dragon, old King Graham decides it's time to pass on his adventurer's hat to younger blood."
- ↑ KQ Collector's Series manual, pg 6
- ↑ The Royal Scribe
- ↑ KQ Collectors Series manual, pg 25