Halo MMO from late 2000s was supposedly killed to protect former Xbox boss' bonus

Doom developer Sandy Petersen shares some information about a game now lost to the annals of time.
Text: Ben Lyons
Published 2025-11-03

There's a timeline where in the late 2000s/early 2010s, we all would have been playing a Halo MMO. According to Doom level designer Sandy Petersen, who also has credits working on Quake and Age of Empires, the now defunct Ensemble Studios was once working on a massively multiplayer online Halo game, codenamed Titan, but it was shut down and axed to protect the bonus paycheque of at-the-time Xbox boss Don Mattrick.

In a post on social media, Petersen claims that "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."

He goes on to add a little about the details of the game, including that you could play as Forerunners or the Covenant, and that the game was set long in Halo's history, way before the era of the Master Chief and the UNSC-Covenant war.

Petersen explains: "You could play either as Forerunners or their enemies, the Covenant. The Flood, of course, was in the game, but not playable. We had quest lines all worked out, homeworlds for all the species, etc. etc."

He also touched on the estimations of the game's success, and how Microsoft expected the game would draw in as much as $1.1 billion, which is immensely impressive especially since we're talking about events in 2008 here.

However, it was axed and shut down, with Petersen laying out the situation as the following: "It was all brought to naught when Don Mattrick realized that his stock bonus was based on the income MS had from games in 3 years.

"You see, we estimated 3.5 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 3 years and he didn't care about Titan.

"All he lost was a game studio who never sold less than 3 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?"

<social>https://x.com/SandyofCthulhu/status/1982965186781954468</social>

Do you think a Halo MMO would have been a big success and would you have played such a project?

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