Eternal Threads is a single-player, first-person story-driven puzzle game of time manipulation, choice and consequence.
As a time-traveling operative, you take on the task of preventing the deaths of six housemates in a 2015 house fire. Rather than directly stopping the blaze, you must observe and alter the decisions made by the characters in the week leading up to the incident to ensure their survival.
The game's core mechanic allows you to freely explore the full seven-day timeline. Using a holographic projector, you can view ghostly reenactments of past events that occurred in the house. These scenes can be paused, rewound, and advanced, giving you the ability to witness how the characters' choices unfold over time.
Crucially, you can directly intervene in certain events, making alternative choices for the characters that ripple forward and alter the timeline. Each decision point presents two options, and selecting one will change how subsequent events play out. This enables you to experiment with different paths, working to find the ideal combination of choices that leads to the best outcome for all six housemates.
To navigate the complex web of timeline changes, the game provides a visual timeline interface. This allows you to easily jump back and forth between different decision points, observe how the story branches, and track which outcomes you have unlocked. The environment of the house itself also dynamically updates to reflect the changes made to the timeline, with new objects appearing and the contents of rooms shifting as the past is altered.
A key challenge is that saving all six housemates is not as simple as finding the "best" set of choices. Each character has their own personal issues and relationships that can be impacted by your decisions. Resolving one character's problems may come at the expense of another's, forcing you to carefully weigh your priorities and find a delicate balance that results in the optimal collective outcome.
Through this blend of time manipulation, branching choices, and consequence-driven narratives, the game allows for a highly emergent and player-directed storytelling experience. Rather than a linear progression, you can approach the game in a variety of ways - following a single character's arc, working backwards from the fire, or exploring the timeline in a more freeform manner. This freedom to uncover the story on your own terms is widely praised as a core strength of the gameplay design.