One of the advantages of working from a home office is that my schedule is very flexible. My wife and I had been trying to talk the kids into going to Disneyland for the past couple of months, but they are at an age where it just isn't that exciting to them anymore. So the two of us decided to take the afternoon off and drive out to The Happiest Place On Earth, leaving the kids perfectly content to remain at home and play Minecraft.
I love Disneyland. My family used to make annual pilgrimages to Disneyland several times a year, and as an adult, I try to visit at least twice a year. (When I worked at Disney Computer Software, I had a Silver Pass that allowed me unlimited free visits to Disneyland, and I would go to the park about once a month).
What has always made Disneyland special to me is what a meticulous job it does transporting visitors somewhere else -- a river cruise through exotic rainforests, a crazy ride through Roger Rabbit's Toontown, a spaceflight to the forest moon of Endor. The illusion is complete enough that we are able to suspend disbelief and get into the spirit of pretending that we are really there. How is the illusion created? Through total immersion, right down to the smallest detail. The staff (or "cast members" as they are called) are all wearing costumes styled for the attraction in which they work, the building fixtures are themed appropriately, and even the trashcans are decorated so that they fit into Frontierland, Tomorrowland or whichever land they are placed.
I try to do something similar with the games I develop. When I produced Rendezvous: A Space Shuttle Flight Simulation, I directed that the message "Program Loading" be changed to "Rolling Vehicle Onto Launchpad." For DuckTales: The Quest for Gold, I wrote the player manual so that it took the form of a "Junior Woodchuck Guide." When planning the quests for Heroes of Might and Magic III, I instructed the writers to make references to the storylines of both the Heroes and Might and Magic franchises, and stay away from corny references to geek-culture found in previous games in the franchises.
Immersion is one of the reasons why players play games. Immersion, when properly done, appeals to our desire for novelty through new and imaginative experience. Although not every player has this desire to a great degree, many types of players do. Game designer Richard Bartle classified MUD (Multi-user dungeon) players into four types: Killers, Achievers, Socializers, and Explorers. Explorers like to explore the world, right down to its finer details. Such details also appeal to to the gamification player type that Victor Manrique classifies as an Enjoyer: players who are motivated by positive emotions such as joy, curiosity, inspiration, mystery and awe.
However, even a tiny detail that is out of place can jar the player out of the immersive experience. Have you ever seen a movie scene in which a spy agency is trying to trick a captive into thinking he was safe somewhere else, only to be made aware that he is being tricked due to a radio playing a sports broadcast from the wrong year or a clock chiming for the wrong time zone? The same thing can happen in games, where an incorrect detail can cause the player to no longer be captivated by your game.