The player uses these repeated time loops to discover the secrets of the Nomai, an alien species that has left ruins scattered throughout the planetary system, including why the sun is exploding.

Running out of oxygen, hitting an object or surface too hard, or being crushed will injure the Hatchling or damage their suit, killing them if too much injury is sustained.

Nothing is brought back with the Hatchling when the time loop resets, with the exception of the data on the spacecraft's computer, which displays the information and mysteries that the player has found so far, organized either by location or in a web of connections.

Each planet has a distinct visual identity, such as Timber Hearth resembling a campsite in the woods with browns and greens, while Giant's Deep has blue-green rocky beaches.

Each planet has a distinct auditory identity as well, with a member of the Outer Wilds space exploration program playing the same song on a unique instrument, which can be listened to from anywhere in the solar system with the signalscope.

No longer able to detect the signal, the Nomai built a civilization throughout the system in order to find the source, dubbed the "Eye of the Universe".

They eventually discover that, with enough power, they can send objects or information backwards in time using a linked pair of black and white holes.

The ending shows a similar planetary system with new life forms 14.3 billion years after its creation, with influences of the Hearthians and Nomai.

The Echoes of the Eye expansion adds an exhibit to the museum at the beginning of the game, which shows off the deep space satellite used to generate the player's system map.

Communicating with the player via a telepathic projection staff, the Prisoner transmits a memory of their crime, which was to disable the signal blocker surrounding the Eye temporarily before they were imprisoned.

The player uses the staff to explain to the Prisoner how their actions led the Nomai to discover the signal of the Eye and enter the system, setting the events of the game in motion.

The development of Outer Wilds began in late 2012 as Alex Beachum's thesis for his master's degree at USC Interactive Media & Games Division.

[13][14] Beachum reused elements from previous projects at the school, including a planetary system changing over time, a planet falling apart, and trees that moved when they were not observed.

[15] He was inspired by the "spirit of space exploration" in an uncontrollable environment in the films Apollo 13 (1995) and 2001: A Space Odyssey (1968), and took cues from The Legend of Zelda: The Wind Waker's (2002) non-player characters that would tell tales of distant lands to entice the player to explore those areas for themselves, and the sense of impending doom of The Legend of Zelda: Majora's Mask.

[15] Beachum kept this as the core of the game thereafter, representing the theme of the differences in scale between forces outside the player character's control and the small moments they could focus on instead.

[15][16] After graduating in May 2013, Beachum took a job at the newly formed Mobius Digital, founded by his classmate Loan Verneau, who had worked on the Outer Wilds project, and actor Masi Oka.

[24] Annapurna, in turn, pushed for the game to be more than a polished student project, and the development timeline was extended, delaying the planned launch from 2016 to 2018.

[35] The game heavily employs a camping motif, reflecting Beachum's personal interest in backpacking while also emphasizing that the player character is far from their home and alone in space.

The title theme was both the first and last song written, as Prahlow recorded himself playing banjo music at the beginning of development and again at the very end to symbolize the growth and change over the course of the game's creation.

The team quickly came up with the central concept for the story: that another race, acting as a foil to the Nomai, had reached the Eye of the Universe first and, afraid of what they had found, blocked the signal.

This necessitated making a small change to the base game before it was released, to ensure that the Nomai did not report detecting the signal at all once they warped into the system.

After initial prototyping, the coin world was scrapped in favor of the ringworld of the final version, with the raft retained but the water monster replaced with the dam breaking.

[43] The swampland of the coin, initially chosen as an unused national park-esque setting, was relegated to the dreamworld, while the ringworld was given a white water rafting theme.

[45] Prahlow returned as the composer for the expansion, incorporating new instruments alongside the ones from the original soundtrack to give the impression of stepping into somewhere new and scary but still anchored to where the player character came from.

Alessandro Barbosa of GameSpot praised the way each step in the loop of discovery "feels like a hard-earned reward", while mrderiv of Jeuxvideo.com said that the game creates a constant desire to solve the next mystery without them being too overwhelming or obtuse.

Game Informer said that "the art style is gorgeous and memorable", while Jeuxvideo said it was simple but pleasing and PC Gamer called it "expressive" and "characterful".

[3][4][5] Several reviewers, such as GameSpot and Mike Epstein of IGN, praised the uniqueness and variation of the planets, and Destructoid called the game setting "bespoke and intimate in scale".

[1][9][52] Eurogamer called out the Nomai writing as particularly of note for giving a "feeling of displaced community, of mutual striving across the extinction barrier".

[66] Alessandro Barbosa of GameSpot and Indee of Jeuxvideo praised the size of the expansion, with Cameron Faulkner of The Verge saying that it was different and large enough to be considered a new game.

[67][71][72] The horror elements received some criticism, however; IGN said only that they were not as good as the rest of the game, but GameSpot called them "frustrating" and "consistently disappointing".