As you may or may not already know, Microsoft and Xbox were developing an MMORPG to compete against Blizzard Entertainment’s flourishing World of Warcraft 20 years ago — long before the latter merged with the former in 2023 with Microsoft’s Activision Blizzard deal. Codenamed ‘Titan,’ development began fully in 2004, with Age of Empires dev Ensemble Studios setting the ambitious project in the Halo universe.
Sadly, though, the project was axed in 2007, and Ensemble Studios itself was shuttered by Microsoft mere weeks ahead of the launch of its Halo Wars RTS in early 2009. The end of Ensemble and Titan has largely been shrouded in mystery for years, though in late 2025, DOOM designer and former Ensemble dev Sandy Petersen alleged then-Xbox head Don Mattrick terminated them to try and safeguard a short-term bonus.
Now, several months later, Petersen has taken to social media once again to reveal further details about the project, including information about its setting, overarching narrative, playable races and factions, and more.
He explains that the game was set before the Forerunners’ Halo rings were fired to wipe out all life in the galaxy in order to stop the parasitic Flood, and featured two playable factions: the “mostly-human” Forerunners (at the time, humans and Forerunners weren’t deemed to be separate like they are in the current canon), and the Covenant.
Petersen notes that the Covenant were “a confederation of aliens who opposed the Forerunners because the latter had built a wall to keep out the Flood,” and that “the Covenant was on the wrong side of the line.” The Covenant would have been similar to the one players know from the main Halo titles, albeit with some new races like “Mimics.”
We had gone quite a long way into the game. We had art, models, and we designers had created missions, and even campaigns. We had classes, races, etc. the Forerunners had 4 “races”: cyborgs, humans, sigmas (humans modified to live & work in outer space), and hardlights (humans… pic.twitter.com/vf2d2c1NgRMay 22, 2026
He then reveals that Ensemble “had gone quite a long way into the game,” with “art, models, and we designers had created missions, and even campaigns.” Classes and races were worked out as well; the Forerunners had cyborgs, humans, sigmas — humans modified to live in space — and hardlights, which were humans that had their essence transferred into a mechanical hard light body.
Interestingly, the idea for hardlights sounds very similar to the Prometheans from Halo 4 and 5, which makes me wonder if 343 Industries/Halo Studios got the idea for that faction from Titan’s unused concepts.
Petersen also noted that he would have been the “lore guy” for the MMO, tasked with “designing worlds and species and ecologies and campaign arcs.” In the end, though, “Don Mattrick murdered Ensemble Studios in its entirety for selfish purposes,” he writes.
“He killed the single most profitable game company they had along with a billion dollar fame. For what? A hope that not paying for Titan’s 3-4 year dev time would increase his stock options. What a loser,” he added.
“You may be sad or you may heave a sigh of relief. I regard it as a great missed opportunity, but I’m certainly not sorry I founded Petersen Games [a tabletop developer] instead,” Petersen said, concluding his thread.
Ultimately, it’s impossible to say whether or not Titan would have done well without knowing more about the MMO in detail, but I’m glad we’ve gotten to learn more about the project and what it would have been about. It’s certainly interesting to think about what might have been if things worked out differently for Ensemble Studios.
What do you think of everything we know about the Halo MMO, Titan? Share your thoughts in the comments, and in our poll.
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