Sierra was known for its habit of putting all kinds of references to itself (or its games) throughout their Quest-series. Rosella owns a barbershop in Leisure Suit Larry II, you can end up in Daventry (or Nottingham) if you press the wrong button in Space Quest I and so on...
Keeping up with this great tradition, there are a lot of references to Sierra games in Romancing the Stones. There are also tons of inside jokes, oddities or references regarding subjects not related to Sierra (such as movie references).
-Clicking the talk-cursor on yourself can result in a line similar to the line in the King’s Quest I remake. (The one mentioning the owl Cedric from King’s Quest V.)
-Possum's name is a reference to a children's book called "Possum Magic" by Mem Fox.
-There are several familiar tunes in the soundtrack. The sharkee music is a familiar Jaws-reference, the theme of the Cloud spirit is based on the theme that played in King's Quest I’s Cloudland, the music during the second cloud test contains parts of the King’s Quest III introduction, and the music during the third part of the cloud test is based on the theme of Mask of Eternity.
-Caldaur is an anagram of Dracula.
-Kolyma's former ruler was called Count Kraestromb. Kraestromb is an anagram of Bram Stoker (the writer of Dracula).
-Llowh'wof (the head monk) is another anagram. When jumbling the letters, you get Wolf Howl.
-Count Caldaur's appearance was modeled after King Ludwig II of Bavaria.
-Countess Lavidia is named after Countess Lavinia from Laura Bow II: The Dagger of Amon Ra.
-Sometimes when trying to get at certain things, you'll get a "'Tis beyond your reach" message (a phrase King’s Quest: Mask of Eternity players will recognize).
-Certain object descriptions were literally carried over from the original. When clicking on certain trees in Wierwood forest, you get the message "Many trees shade your way as you journey through the land of Kolyma." This was the general room description of most regular screens in the original King’s Quest II.
-Try using the mallet on the pumpkin baby while you're carrying it, or the pumpkins growing in the patch.
Northernmost beach screen
-Talking to the hill results in a reference to "The Sound of Music."
-Talking to the rocks jutting out from the sea will sometimes net you a "Rocky and Bullwinkle" reference.
-There's a slight chance of a very familiar Easter egg appearing whenever you enter the screen.
-The foliage near the rock arch is Republican.
-Talking to the skulls might end up in them talking back. One of them is Bonehead from Quest for Glory.
-Clicking the talk-cursor on the stump will reveal a Forrest Gump reference.
-Clicking the talk-cursor on the log near the stump will reveal a "King's Log," a Star Trek reference.
-Clicking the hand-cursor on the ground will reveal a message regarding the film "Finding Forrester."
-One of the bushes here was imported from Texas.
-Talking to the rocks will reveal a reference to Queen.
-The symbol above the gate is the typical King's Quest symbol that's also displayed on the grey title screens of the King’s Quest I remake, the King’s Quest II remake, King’s Quest V, and King’s Quest VI.
-Talking to the "pillars" of the town gate will reveal a reference to the Microsoft Man.
-On top of the file cabinet are several game boxes of past Sierra games.
-Talking to the grandfather clock will sometimes reveal a Beauty and the Beast reference (Disney's version, that is).
-Clicking the hand-cursor on the piles of books reveals a Mary Poppins reference.
-Clicking the talk-cursor on the same piles mentions Teddy Ruxpin.
-One of the books mentions the guidebook to the Land of the Green Isles. This guidebook was included with King’s Quest VI.
-There are TONS of references among the contents of the shelves. Among them are several King’s Quest VI references, a few Quest for Glory references, and some references to movies and books. The book called "Future's History" is the title of Daniel Stacey's Space Quest fanfic.
-Clicking talk on the shelves will reveal a reference to the bookworm from King’s Quest VI.
-The final book the librarian lets you read contains some references to other King’s Quest games.
-The mallet near the entrance belongs to a character from Quest for Glory I.
-The dragon head is either the Dragon of Doom or the dragon image that appears when casting the Dragonfire spell from Quest for Glory V.
-The little can on the right of the droid contains 7-up.
-The little droid on the shelf is the retrieval unit from Space Quest I.
-The sorcerer's hat belongs to Simon the Sorcerer (another adventure game).
-Clicking the talk-cursor on the magical carpet before taking it gives you a part of the song "A Whole New World" from Disney's Aladdin, not to mention the fact that Aladdin's name is (partly) inscribed on the carpet.
-The genie's name (Ni'Bor Si'Ma'Will) is an anagram of Robin Williams, who did the voice of the genie in Disney's Aladdin.
-Talking to ordinary fish reveals a misquote from Alien.
-Talking to the seaweed in certain screens reveals a line from "Under The Sea," a song from Disney's version of The Little Mermaid.
-Talking to the sky reveals a reference to a song from R. Kelly.
-Talking to the snake may reveal a reference to Harry Potter.
-Putting your hand in the hole in the rock near the entrance of the enchanter's cave will reveal a shameless plug for an upcoming project from AGDI (in the spirit of the Space Quest I plug in the original King’s Quest II).
-The name of Graham's pal in the first test (Malvolio) is the name of a character of Shakespeare's "The Twelfth Night." The name literally means "I mean ill will." The same play is also mentioned if you try to enter the northern or eastern part of town too many times.
-Selecting the right options will reveal a hidden option in the third test. You won't be able to obtain the perfect score by selecting this option, but "The Madness of King Graham" is simply the most brilliant Easter egg in the game.
-Clicking the hand on the church bell reveals another reference to a Sierra-game.
-One of the graves in the cemetery behind the church contains a reference to Quest for Glory.
-Getting dragged into a grave in either graveyard will let you hear a Psycho-like death theme.
-There's a reference to Olga and Boris from Quest for Glory IV on one of the tombstones.
The message on the tombstone near the one mentioned above contains a randomly determined message about:
-The two switched bodies, Lord Christopher Eveer and the healer Larmon Odnarb, are anagrams of Christopher Reeve and Marlon Brando. These two actors played Clark/Superman and his father Jor-el in Superman.
-Showing the key from the black book to Anastasia will trigger a comment about the odd object placement in the original King's Quest game.
-Talking to the candelabra reveals another Beauty and the Beast reference.
-Clicking the hand on the barrels will trigger a reference to Mask of Eternity.
Door of Destiny
-Selecting the wrong realm will warp Graham to one of the other Sierra series (or into another King’s Quest game). You'll die though.
-Clicking talk on the cliffs will reveal a Wizard of Oz reference.
-Attending the wedding is the subject of one of the previous Easter Eggs as well as Anonymous Game Developer 1, Anonymous Game Developer 2, Daniel Stacey and Tom Lewandowski (the main members of the AGDI team).
There are several characters from the King’s Quest I remake in the audience in Daventry's throne room.