During the Xbox Partner Showcase, a new trailer debuted for studio Owlcat Games’ upcoming sci-fi title. The Expanse: Osiris Reborn, is set in the universe of the beloved books and show. After chatting with the developers, I have a clearer idea of just what story the game will tell. Best of all, players will get to try it out next month.

The Expanse: Osiris Reborn, due out in Spring 2027, was first revealed at Summer Game Fest last year, with a cinematic peek at the game, but the new trailer shows gameplay footage to give players a sense for what’s waiting for them in the full release. With cover-based combat, squad coordination, abilities and a space sci-fi setting, the game looks a lot like BioWare’s beloved Mass Effect trilogy from the 2000s — which is just one of several games that inspired Osiris Reborn.

Franchise fans won’t have to wait long to get a taste of the game. The closed beta will arrive on April 22, 2026, providing a full mission for gamers to field a three-person squad to defeat enemies with their gunplay and abilities. Players will get to choose between preset character builds with different origins: An officer or a hacker, either a man from Earth or a woman from the asteroid belt (called a Belter in the universe’s parlance). 

The playable beta will also lend insight into the game’s connection to the books and show. It takes place after the alien protomolecule first spreads through Eros station and before the extrasolar Ring is activated (e.g. between the end of season 1 and the middle of season 3 of the TV show). Through the mission, players will collect materials to upgrade their equipment, improve their skills and use magnetic boots to walk up and down surfaces experiencing zero-G, traversing walls and ceilings.  

It’s a small glimpse at what the final game will deliver. Ahead of the Xbox Partner Showcase, Owlcat developers gave the media a chance to ask their burning questions about the game in a group interview, from how it connects to the greater story told in The Expanse media to how it takes inspiration and differs from Mass Effect.

What The Expanse: Osiris Reborn does differently from Mass Effect

Just looking at The Expanse: Osiris Reborn’s new trailer reminds me a lot of Mass Effect, and there are plenty of other similarities. The upcoming game’s combat is heavily based on cover shooting. There are six companions to recruit (and potentially romance), from which players will draw to fill a three-person squad into missions alongside their main character. 

After hearing from Owlcat Studios developers, that’s no accident — when I asked them in the preview about it, they noted that many on the team played and loved those games. What they took from it was “the feeling, the impact on the player that Mass Effect had,” game design producer Yuliya Chernenko said. 

Leonid Rastorguev, the game’s director, acknowledged Mass Effect’s influence on the team, but in contrast he insisted that Osiris Reborn will stand out on its own apart from BioWare’s beloved games.

“In many ways that we do differently, the ways we address the relationship development between companions and the captain [main character], it resembles more of how we do it in our more narrative-driven RPGs like Pathfinder,” Rastorguev said. Osiris Reborn isn’t class-based, either, giving players more freedom to customize their weapons and gadgets.

More importantly, Osiris Reborn is set in the universe of The Expanse, a more realistic sci-fi space opera set within the closest planets of our real-world solar system, where different cultures develop between the native Earthers, the militaristic Martians and the working class Belters in the asteroid station archipelago between Mars and Jupiter. 

While the books and show follow the heroic James Holden and crew of the gunship Rocinante, Osiris Reborn will center on a new character from one of those three origins, and their interactions with companions and others will be colored by the cultural clashes from differing backgrounds. Since the game takes place during the first two seasons of the TV show (or first two-and-a-half books, say the developers), there’s plenty of conflict between these three mega-nations.

“We aim to make this game as welcoming to people who don’t know about The Expanse … to join as everything is unraveling, to see the major events that happened in the series but from a different point of view,” Chernenko said. “It was a little bit challenging to give freedom of choice to a new character with their own story, with their own goals within the already-set timeline of events.”

And while beloved characters from the books and TV show will make cameos, the team was tight-lipped about their identities. 

Making an action RPG in The Expanse’s gritty sci-fi setting

Also unlike Mass Effect (or any of BioWare’s games), player choices won’t shift them up or down a good-and-evil scale. Instead of a moral alignment system, the player character’s decisions that involve and deeper involvement with the game’s factions (Earth, Mars and the Belt) affect their reputation. I found that reassuring. It reflects the shades of gray that permeate The Expanse as a setting, since backroom politics, risky deals and betrayals make up a lot of the drama in the books and TV show. 

Similar to The Expanse’s Rocinante, players will have their own ship to call home between missions. The developers noted that it won’t have a customizable appearance, though. It’s just a space that changes as the story progresses, with more companions coming onboard. While there will be some interactive components, it’s more a place to chat with squadmates and rest, akin to a campsite in classic RPGs, Rastorguev said. 

Plenty of games influenced the team beyond Mass effect. For the cover combat, the team turned to The Division, Gears of War and Uncharted series, Rastorguev told me; for companions, they looked to The Last of Us. 

“If we list all the references that we had during the development cycle, it will be a huge list, including some very strange games like Dark Souls, the Persona series and others that you can’t really place where we put the inspiration from without knowing the inside kitchen of the development cycle,” Rastorguev said. 

Chernenko noted that the team brings in a lot of influences from different books and movies, making it tough to source specific inspirations for certain things in Osiris Reborn, with one exception: figure skating.

“We can share that the figure skating inspiration was for the sprinting animation in the zero-G section,” Rastorguev said.

The game’s zero-G mechanics may also differentiate Osiris Reborn from its influences. Guns and munitions will operate the same way with or without gravity, though there are some tweaks: grenades will have little propulsive jets, for instance, and explosives leaving trails of fire will have an in-universe reason they don’t instantly extinguish in a vacuum. But movement will be different, as the player’s squad enters missions with magnetic boots that allow them to walk on walls and other surfaces — a signature element from the books and TV show.

In Osiris Reborn, companions are key 

Another important feature from both The Expanse and BioWare’s games are relationships — and yes, there will be some romances between the player character and companions, Chernenko said. Developing connections with companions is a big part of the game, helping them with problems and even going on so-called loyalty missions famous in BioWare games to earn their trust. 

“Companions play a significant role,” Rastorguev said. “They have their opinions, their remarks, and even if they are not in combat with you in your combat group, they are still reaching out, doing some important stuff or at least giving comments on what’s happening during the mission.”

Lastly, I asked whether the game drew more from the books or the TV show, since there were some changes made when abridging so much of the original text into serial television. Osiris Reborn takes more influence from the show, though they did include things only mentioned in the books. 

“We try to make sure that both worlds, both points of view are taken into account,” Chernenko said. “But in terms of visual stuff, like the main characters and what’s happening story-wise, it is the show, not the book.”