The Expanse: Osiris Reborn could be the Mass Effect successor we've all been waiting for (preview)

It's always nice to see a studio level up in real-time. Owlcat has been a beloved studio for many years, producing top-down RPGs like the Pathfinder series. However, The Expanse: Osiris Reborn marks a major shift for the Cyprus-based studio. Not only is it their first third-person RPG, but it represents a substantial effort to adapt an already well-established and beloved IP with AAA production values.

During Gamescom 2025, we sat down with Owlcat Games and saw a beefy 60-minute demo of this hotly anticipated upcoming space game. At the same time, we got to ask both of them questions and really dig into the goals they have with The Expanse: Osiris Reborn.

During those sixty minutes, we saw an impressive RPG that looks set to be the proper follow-up to the Mass Effect Trilogy fans have wanted for more than a decade, with a lot of its own gameplay twists and mechanics that feel exciting for the genre. However, for hardcore fans of The Expanse, the game is firmly rooted in the political thrills and far-reaching lore of the IP. Can they strike a balance and keep everyone happy? The early signs look good.

Rooted In The Source Material

The Expanse: Osiris Reborn is an original story set alongside the first two books (and the first two and a half seasons of the TV show). In fact, the studio has been inspired by the dramatics and visual style of the show when it comes to the cinematics and story missions. Osiris Reborn is completely intertwined with the events of the show. The world’s factions, political systems, and world are all here; you can tell that Owlcat is treating every aspect of Daniel Abraham and Ty Franck’s world with the utmost care and attention.

Key moments that appeared in the show, like iconic video footage from key figureheads, will appear in-game. Plushie models of famous in-universe TV show cartoon characters may be found on a desk.

None of this means newcomers won’t find something to grasp onto here, though. The likeable characters and classic Mass Effect-style third-person gameplay provide an enticing hook, and the original story gives newbies a fresh entry point into the franchise.

You can play as the Earthers, Martians, or Belters, with notable differences between each option. One character in the demo, Larry, is a Belter and is significantly taller than the other characters, and his speech and behaviour reflect that of the Belters. Whichever gender you choose, you will have a sibling of the same gender, forming the personal backbone of the main story, where you play as a Pinkwater mercenary.

Throughout the game, you'll meet new companions, each with their own specializations, personalities, and traits that can affect gameplay, the story, and even the dialogue options and choices you have. A companion may offer a solution to repel an enemy boarding action, while your player character has another method — it's up to you to choose which path to take, but ignoring your associate's advice could affect your relationship with them down the line.

Mass Effect is back, in all but name

The Expanse: Osiris Reborn owes a lot of its gameplay DNA to Mass Effect. It is a classic cover-based third-person shooter with a wealth of abilities mixed in there, like cover-piercing rounds and the ability to highlight enemies through walls. You can customize your character and also choose a base playstyle. There are no classes, and the game is not interested in locking you out of using certain equipment or weapons. Instead, they form a baseline for your character that you can then build around with weapon choices or skills.

You can combine skills, weapons, and equipment to tackle enemies and different threats, adapting on the fly for each encounter. Shielded foes will charge into you, and others will sit back and hide behind cover, forcing you to draw them out.

You can also lean on your companions quite significantly in battles. You can have two alongside you in fights, but we only had one in the demo (our sibling). Each companion can be directed to complete certain actions, telling them who to attack, or instructing them to interact with the environment; it's reminiscent of the contextual "Call To Action" mechanic in the Marvel Guardians of the Galaxy game.

A prompt appears when a nearby environmental object is interactable. These can destroy or create sections of cover, or even topple parts of the world — like ceiling fans — down on your enemies' heads for a brutal kill. Each companion has their own way of doing things.

Owlcat said that one clear way it “wanted to differentiate ourselves on the market” is that even the companions who aren't with you will play a role in missions. That can be talking over comms with the player, offering up options to tackle objectives, or — in the example in our demo — helping out with air support and targeting enemies from outside the ship. This means the companions you don't choose to fight alongside aren't disappearing into the ether for 40 hours as you use everyone else.

The companion and combat systems are incredibly robust and well-thought-out. We've only played a small section, but so far, no mechanic, system, or idea seems like it has been underutilized or a half step. This is a proper evolution for Owlcat and one of the most feature-rich RPGs I can remember in recent years.

The game is structured into a number of explorable zones with side quests, secrets, and hidden loot chests to find, but it's not an open world in the traditional sense. There will be side missions too — many of them missable — so it pays to explore and talk to everyone you meet, something that RPG fans don't need to be told twice.

Some secrets are hidden behind stat skill checks, like science and persuasion, and across the game, you are investing in these skills and building out your inventory of weapons, armor, and equipment — either by buying or looting them. There is no RNG to stat skill checks, though; it's a simple pass or fail system depending on how many points you have.

Blow it all to pieces

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One final thing that stuck out during our demo is the graphical fidelity and tech behind The Expanse: Osiris Reborn. Character models and lip synching are all top-notch here, and it feels like a big-budget title when it comes to production values.

Exploring the outside of your ship shows some gorgeous views of space with great lighting and a solid soundtrack. The game also had real-time orbiting represented, which we found particularly impressive, as you can see your ship spinning through space when you're floating around.

Sound is muffled when fighting in space to reflect the lack of an atmosphere, and there is a real-time physics system in place that means enemies and objects will float off into the distance based on the force that hits them or the direction they were thrown.

Additionally, there is an impressive level of detail and environmental destruction. Walls inside the ship fall apart as the signage, paint, and outer shell take damage from bullets, and you can completely destroy some weaker cover in combat

Those environments can also change based on your choices during key story moments. We chose to attack the invaders instead of surrender, and towards the end of the demo, the ship's corridors were torn to shreds and plastered in bodies from fights that broke out before we arrived.

After seeing more than 20 games at Gamescom, The Expanse: Osiris Reborn has been the highlight of the show, and it was one of the best pure gameplay showcases for a game we have seen in a long while. It still has a way to go, but Owlcat seems poised to have a breakout moment with Osiris Reborn, and fans of Mass Effect and The Expanse universe will be delighted with the respect and care that is being infused into every pixel on screen and every mechanic at play.

The Expanse: Osiris Reborn is coming to PC, PlayStation 5, and Xbox Series X/S. We don't have a release date at this time, but we'll keep you posted as more info drops.