

The player character has health, fuel, and oxygen meters, which are replenished when the character returns to the ship or by finding trees or refills. This process gradually reveals the secrets buried on Ash Twin while simultaneously making the Ember Twin cave system inaccessible later on in the time loop. One example is the paired Ash Twin and Ember Twin planets orbiting so close to each other that sand from Ash Twin is funneled over to cover Ember Twin during the loop. Some events and locations change during the course of the time loop, which means that areas and puzzles are often only accessible at certain times. All areas of the game are technically immediately accessible to the player upon acquiring the ship launch codes, however many areas are protected by logic puzzles which can often only be solved through learning more of the Nomai and speaking to fellow space explorers. The central premise of the game is exploration, with the player compelled to uncover the remains of the Nomai civilization to find the cause of the time loop and complete the game. These codes, and the knowledge of them, are the same across subsequent loops, allowing the player to immediately launch the ship without first visiting the observatory. For example, in order to use the ship, the player must get the launch codes from colleagues at the local observatory. In the first part of the game, the player links with an ancient Nomai statue which ensures that the player retains information discovered in each time loop when it restarts.

Thus, the player is encouraged to learn why by exploring and uncovering secrets of an extinct race known as the Nomai, who previously colonized the solar system hundreds of thousands of years ago. Outer Wilds features an unnamed player character exploring a solar system that is stuck in a time loop, going back 22 minutes before its star goes supernova.
