Osiris Reborn FAQ: Open World, Co-op, Ship Combat & Length

Every format question at a glance

Is it open world?

No. There is an unskippable opening, and then the game opens up: you choose where to go from your ship. Rastorguev listed Earth, Luna, Mars, Ceres Station, Ganymede and Io at Gamescom 2025, and said it is “not a linear story-driven game. There is a lot of side content.” Previews describe semi-open levels with side missions. Travel between stations is not a flight sim. Where you can land early depends on your origin.

Multiplayer, co-op and perspective

Steam lists only “Single-player”, and no co-op mode has been announced. It is played in third-person with over-the-shoulder, cover-based shooting. The Expanse Fandom wiki calls it first-person. That is an error: the store description and the press release both say third-person.

Ship combat and the Gemini

Your ship is the Gemini, described officially as the most advanced ship in the solar system, and your crew is “the Gemini crew” (see companions). You do not fight in it. Mishulin: “There is no huge mini-game that allows you to play ship combat… but traveling on a spaceship is very much part of The Expanse and we want you to feel that.” Combat is on foot, including zero-G sections with mag boots.

How long is it?

About 20–30 hours. Rastorguev: “about the length of Clair Obscur: Expedition 33. So you can expect 20, 30 hours of gameplay.” Producer Chernenko added that it is “definitely not as long as our previous games”, which is a useful contrast: Pathfinder and Rogue Trader routinely run past 100 hours. The Beta covers one mission, about 1–2 hours.

Is it like Mass Effect?

Owlcat says so itself. Producer Chernenko: “The original Mass Effect trilogy was absolutely an inspiration to the team.” The shape matches: third-person cover shooting, two companions in the field, a ship hub and romance. Owlcat also confirmed the Mass Effect 2 suicide mission inspired how crew members off the field can still help.

The differences Owlcat claims are no fixed classes (four open skill trees plus gear), origins, and heavier choices and consequences. The details are on the character creation page.

Choices and endings

The official “The Choices You Make” dev blog (August 18, 2026) is the best source here. Your decision on Pinkwater 4 can destroy or spare the station, and it comes back later. Earth, Mars and the Belt remember what you do, which “affects how their stories unfold, including the fates of important characters.” A hidden archetype system tracks how you behave and shapes the epilogues. How many endings there are has not been announced.

Still unannounced

• New Game Plus. Not in any official post or interview we checked.
• Mod support. Not announced. Owlcat’s earlier games supported mods, but that says nothing about this Unreal Engine 5 title.
• Difficulty levels. The official Beta guide covers tactical pause and cover, but no difficulty menu. GamingTrend’s Beta preview mentions a choice of Normal or Hard ⚠ one preview.
• Age rating. Not settled. The Xbox store lists ESRB Mature 17+, while the PlayStation Store still says rating pending. Steam shows auto-generated regional ratings, USK 16 in Germany and DEJUS 16 in Brazil ⚠ store data only. No PEGI rating found.

Osiris Reborn vs Starfield

Owlcat has never compared the two, so this is our reading of official facts. Osiris Reborn is a 20–30 hour story RPG in one solar system, with a fixed ship, no ship building, no ship combat and hand-built locations. Starfield is an open-world Bethesda RPG with procedural planets and ship building. The closer comparison is Exodus, another 2027 Mass Effect-style RPG with no connection to The Expanse (see timeline).

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