Doom designer Sandy Petersen alleges former Xbox boss Don Mattrick killed Ensemble Studios and its Halo MMO to protect his personal stock bonus: 'Don started as an EA hatchet man so what would you expect?'
Doom level designer Sandy Petersen has taken to X (formerly Twitter) to explain the closure of Ensemble Studios, where he worked in the 2000s. According to Petersen, Ensemble and its in-development Halo MMO were scuttled by Xbox boss Don Mattrick to protect a short-term, profit-based bonus he was elligible to receive.
"In 2008, Ensemble Studios started planning a gigantic MMO set in the Halo universe," said Petersen. "We code-named it Titan. It was to take place tens of thousands of years ago, before the Halos were set off & destroyed all sentient life in the Galaxy."
Petersen was in charge of sketching out the setting and lore of this primeval Halo galaxy, and he said that Titan was at an advance stage in development when it was canceled, which is corroborated by prior accounts of the game's development—here's an album of screenshots and in-game models allegedly sourced from the project.
Petersen claims that the "lowest estimate we & Microsoft had for the game's total income was $1.1 billion," which is a staggering sum for any game to pull in. For context, Deadline reported in 2021 that the entire Halo franchise had reached 81 million copies sold at the time. Back of the napkin math at $60 a copy puts the series' revenue from game sales at around $5 billion after 20 years of existence.
While possibly a typo, Petersen's note that Titan started development in 2008 doesn't line up with prior accounts of the game's development which have the project starting in 2004 and getting canceled in mid-2007, around Don Mattrick's July, 2007 ascension as head of Xbox.
In 2008, Ensemble Studios started planning a gigantic MMO set in the Halo universe. We code-named it Titan. It was to take place tens of thousands of years ago, before the Halos were set off & destroyed all sentient life in the Galaxy. I was in charge of the universe-building -… pic.twitter.com/8eaSbEt81XOctober 28, 2025
Petersen said that Titan's Alliance and Horde would have been the human-like Forerunners and the Covenant. Some of the leaked art and screenshots of Titan look contemporaneous with the mainline series, while other designs have a more science fantasy look in line with what Petersen describes.
It's possible that Titan might have involved time travel of some kind, or else a consistency with the setting's supposed far future aesthetics like we saw in Star Wars: Knights of the Old Republic. In a 2008 ShackNews interview, former Ensemble technology director Dave Pottinger said that "the Covenant weren't quite the Covenant yet" in Titan, which could gel with Petersen's characterization of the game's story—a distant past Covenant in all but name opposing the more or less human Forerunners.
"It was all brought to naught when Don Mattrick realized that his stock bonus was based on the income MS had from games in three years," said Petersen. "You see, we estimated [three and a half] years to finish Titan if we did it right. And that’s beyond Mattrick’s drop dead date. So by firing ALL of Ensemble, he didn’t have to pay for our expensive studio for three years and he didn’t care about Titan.
"All he lost was a game studio who never sold less than three million copies of everything we made. I don’t believe he did justice to Microsoft stockholders but hey—Don started as an EA hatchet man so what would you expect?"
A harsh assessment of the former Xbox honcho, and this isn't the first time Petersen has recounted this story. Last year, Petersen discussed the downfall of Ensemble and Mattrick's role in it on the Bored With Nelly show on YouTube. Petersen doesn't elaborate if he's seen concrete evidence indicating that this was Mattrick's motivation, or if this is his assessment based on Ensemble's closure and Mattrick's contract.
Ensemble's shutdown certainly made little sense for Xbox's long-term health and profitability: Petersen and Pottinger both pointed out that the studio's games were consistently successful from a sales perspective.
"They have a plan. We're not in it the way that we used to be," Pottinger said back in 2008. "They're making the choice that they need to make to be profitable, and make the right choice for the shareholders and things like that. It's hard to look at the stuff Ensemble's done and equate those two things, and justify it in that sense."
Mattrick's time leading Xbox is not recalled fondly by fans. Under his leadership, Xbox invested in Kinect, the dashboard redesign (complete with knockoff Miis), and other initiatives clearly attempting to replicate the Nintendo Wii's shocking success, seemingly to the detriment of Xbox's established audience.
This culminated in the launch of the Xbox One, and its initial marketing as an always-online media center, which kicked off a series of console generations where Sony has maintained a commanding lead over its once-threatening competitor in the console market.
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