Stardew Valley is considered by most as one of the best farming and life simulator RPGs to date. Especially with its latest 1.5 update release, Stardew Valley is packed with multiple features that allow for immense replayability. One of these features is the secrets and mysteries that are hidden throughout the game.
During a playthrough, the player will come across some weird things that seem to make no sense. And more often than not, they won't. There are some unexplainable facts spread throughout the game and despite fans having come up with some theories about them, these theories still create more questions than they actually answer.
Rain Noises
Stardew Valley is full of weird, unexplained events, and one of them is the weird sounds that can be heard on a rainy night as showcased by a fan. These sounds definitely give players the chills, and have no direct explanation.
One theory is that the coyote sound refers to a coyote that attacks and kills some of the farm's animals if the coop and barn doors are left open overnight. However, there is no theory about the other sounds, which makes this really creepy.
Lonely Stone
The Lonely Stone can be seen on the map, in the sea right next to the docks. If the player clicks on it from the map, a stone-breaking sound can be heard (similar to the sound that breaking stones make while mining).
Afterward, the player gets kicked off the map screen and goes back to the inventory menu. The lonely stone still remains a mystery and fans wonder why it's even there.
Abigail's Father
Even though Abigail is presented throughout the game as Pierre's daughter, there are facts throughout the story that say otherwise. As revealed in one of Abigail's dialogues, her mother forbids her from meeting the wizard.
She is also the only villager (other than the player and the wizard) that can see the Junimos. In a later scene between the player and Caroline, Caroline reveals that in the past she saw Pierre cheating on her, and to get back at him she dated the wizard. In the end, she reveals that Abigail is actually the wizard's daughter.
Skull Cavern Plaques
Located throughout the Skull Cavern walls, there are some plaques filled with symbols that initially seem to make no sense. However, many fans have tried deciphering them, and through trial and error, have come up with two main translations.
One of the signs translates to "we are cursed, too much iridium", while another to "wizard sealed us in this prison until the day a hero puts us to rest". Perhaps the first one refers to the purple slimes in the Skull Cavern, while the second to the creation of the cavern in general.
Main Menu Alien
While in the main menu, before clicking new/load game, the player can click on the 'E' letter of Stardew 10 times in order for an alien to appear behind the letter.
After smiling for a few seconds, it disappears again and the menu goes back to normal. There seem to be more than a few secrets referring to aliens which raise a lot of questions that have no answer yet.
Flying Ufo in the Shipping Screen
After sleeping, the player sees the shipping screen where the profits of the current day, as well as the date, are shown. On the 24th day of winter, Santa Claus appears on top of the screen.
However, if it's not the 28th, and there was no rain, the mystery is that there is a very small chance that for a flying U.F.O. to appear on the top of the screen. This is another reference to aliens that leaves players wondering.
Alien Capsule Event
Stardew Valley includes multiple farm events that have a small chance to occur overnight. One of the most mysterious events is the appearance of a weird alien capsule on the farm. It appears as if it's filled with something (like an incubator ready to hatch), but the player can only move it around, not open it.
The mystery is that after a few days, the capsule is found broken as if the thing inside finally broke out and left. The player never learns what was inside, and the alien capsule is one of the biggest mysteries in the game.
Villagers and Slimes
A unique fact about slime incubators is that they can be placed anywhere, not only on the player's farm. Interestingly, placing them in the town and hatching slimes there allows for some unique interactions between the slimes and the villagers.
Slimes incubated there will act, and be treated like normal villages by everyone else. Villagers will say hello to them, and the slimes will greet them back.
Spouse & Slimes
Another unique interaction regarding slimes is the one between the slimes and the player's spouse. If the slimes are incubated inside the player's home, and the player has a spouse, then slimes will attack the player but not the spouse.
On top of that, the spouse will attack, and kill slimes in one hit. Perhaps the spouse is defending the player from the aggressive slimes.
Yoba
Yoda is considered to be the deity of Stardew Valley with him having a shrine in the back of Pierre's general store. People are praying to him there every Sunday. Throughout the game, multiple dialogues between the villagers reference Yoba, without however having him play an important role in the story.
Also, there is a book in the library that refers to Yoba as the god who created the world. Nevertheless, not much is known about him, and he is more of an unexplained filler side-story.