Easter Eggs: What They Boil Down to
Specific gaming developers, franchises, and companies of simulator games, and games in general, are known for their use of Easter Eggs for players to find. An Easter Egg, to clarify, is something unexpected or undocumented in a piece of computer software meant for humor , a message, image, bonus material, etc.. This can be done in a variety of games, not necessarily just simulator games, but adventure, action, RPG, MMOs, puzzles, and more. Games have been doing this since the beginning: Adventure (1979) on the Atari 2600 is given the title of the first game to have an Easter Egg for the player to discover. Today, Easter Games are common within gaming culture and often searched for in order to learn more about lore, narrative, or to gain a further understanding of the game story. Some of the more notorious ones in more recent years are big name game franchises such as Doom, Assassin's Creed, Fallout, Bioshock, GTA, Call of Duty, Portal, Zelda, and many more. Easter Eggs in these larger franchise games often appear as jokes, messages, images, references, interesting finds, and will sometimes offer more for the player in terms of lore or narrative. Other notorious games known in the indie gaming community for their Easter Eggs include Five Nights at Freddy's, One Shot, and Undertale.
Indie Gaming Easter Egg
Looking at Simulator games as more indie in gaming culture than not, the concept of working a mediocre job or performing a task replicated from the real world leads the player to want more, to have context and narrative for the purpose of the game often times. Instead of simply doing the assigned "job" (i.e. Mr. Penumbra's 24-Hour Bookstore), there is a tendency to search for clues, extra content, and simply MORE. Five Nights at Freddy's games do this exceptionally.
Each game is littered with Easter eggs. Typically the games exhibit the need for the player to find the Easter eggs to learn more about the lore and context of the story. Such as Mr. Penumbra's 24-Hour Bookstore, the game has a need for the player to find the hidden content to learn more and proceed in the game. More often than not, the game falls to the player to get the Easter eggs to get the "good" ending where the "souls of the children" are then released or redeemed (if you haven't played the game, spoilers).