That Which Remains co op allows one to four players to team up online in a sci-fi ghost-hunting horror extraction sim developed by Remaining Games and published by Interdimensional Games Inc. Playing as conscripted Relics retrieved from an older era of human suffering, your squad travels across contaminated time periods to identify and capture hostile entities to harvest Enticine—liquefied trauma—for a futuristic utopia.
Here is everything officially confirmed regarding how cooperative play, proximity voice communication, and team survival operate in the game.
Co-Op Team Size and Lobby Structure
According to the official Steam listing and developer announcements, That Which Remains is designed from the ground up for 1–4 players in online PvE co-op.
- Squad Capacity: You can enter incursions solo or with up to three other Relics in an online party.
- Continuous World: The game uses a continuous world design with no loading screens after the initial launch, keeping teams immersed between missions and base operations.
- Full-Body Awareness: Player models feature complete physical representation. Other teammates can visually see exactly what tools you are holding, where you are aiming, and what actions you are performing in real time.
Voice Chat, Walkie-Talkies, and Fallen Relics
Communication plays a direct gameplay role in That Which Remains rather than just serving as team chat. The developers built realistic audio systems that dynamic threats can interact with:
- Proximity Chat and Acoustics: Local proximity voice chat features per-room acoustics, meaning audio echoes, muffles, or carries depending on interior walls and environment layout.
- Walkie-Talkies: Squad members separated across large contamination zones can use handheld radios to communicate over long distances.
- Entities Are Listening: Hostile entities react to spoken player voices picked up through microphones. Speaking loudly or carelessly can draw hostile manifestations directly to your position.
- Spirit Box Comms for Dead Players: When a Relic dies during an excursion, they are not completely removed from the session. Surviving teammates can use the in-game Spirit Box to talk to fallen teammates, allowing deceased players to provide warnings, relay entity locations, or create chaotic distractions.
Core Co-Op Extraction Loop
In co-op excursions, players work together across five initial contamination zones (ranging from a rural farmhouse to a sprawling arctic prison). The mission structure revolves around three shared objectives:
- Investigate and Identify: Teammates coordinate using roughly 18 different tools, including EMF meters, temperature monitors to track sudden freezing drops, cameras to spot ghost orbs, and spirit boxes. The squad cross-references signatures against 12 entity types to log their traits and moods.
- Capture the Manifestation: Unlike standard ghost-hunting titles where you simply log evidence and leave, Relics must actively capture the entity or use traps to extract Enticine from it directly. Entities fight back by throwing objects, manipulating electrical systems, slamming doors, or possessing players.
- Fulfill the Daily Quota: Squads must carry harvested trauma canisters back through the portal and submit their daily quota before the 24-hour cycle expires.
Surplus Enticine is automatically converted into base power. If your team fails to generate enough power or meet the quota, your base systems begin shutting down.
Shared Base Features and Sanity Management
Sanity is a persistent mechanic shared across days, combining fatigue, mental strain, and fear. Between hunts, squads return to their shared facility hub to regroup and recover:
- Sanity Recovery: Players can unwind inside the base by sleeping in their cabins, drinking coffee, shooting hoops on the indoor basketball court, playing chess, or resting in the unlockable Serenity Chamber.
- Base Upgrades: Relics spend team surplus power and Energy Credits to craft new equipment, unlock personal stat upgrades, and install base improvements across 10 base upgrades.
- Persistent Cabins: Personal player quarters and room decorations persist and travel with your profile across different multiplayer games.
Co-Op Feature Breakdown
| Feature | Specification | Official Detail |
|---|---|---|
| Player Count | 1–4 Players | Online Co-op and Solo play supported |
| In-Game Voice Chat | Proximity & Radio | Per-room acoustics, walkie-talkies, and entity voice detection |
| Downed/Dead Relics | Spirit Box Interactivity | Living players can speak to deceased squad members via Spirit Box |
| Shared Objectives | Extraction & Quotas | Capture entities, extract Enticine, and hit 24-hour power quotas |
| Base Activities | Shared Hub | Crafting stations, basketball, chess, sleeping cabins, sanity recovery |
| World Loading | Seamless | Continuous world with zero loading screens post-launch |
Release Date and Free Demo Details
That Which Remains is scheduled to launch into Steam Early Access on October 27, 2026.
Ahead of the Early Access rollout, Remaining Games released a free playable demo on Steam during Steam Next Fest. The developers confirmed on the official Steam community hub that all progress earned during the free demo transfers directly into the main game upon release.
Frequently Asked Questions
Can you play That Which Remains solo without a team?
Yes. The game features full single-player support alongside its 1–4 player online co-op mode. Solo players handle the investigation, capture tools, and quota extractions on their own.
Does That Which Remains have local split-screen multiplayer?
No. The official Steam store page lists Online Co-op only. There is no split-screen or local shared-screen co-op option.
Can hostile entities hear players talking in co-op?
Yes. The game integrates microphone detection via V.O.I.C.E. technology. Hostile entities track player speech, react to specific phrases spoken into spirit boxes, and hunt players who make too much noise over local proximity chat.
