A former Ensemble Studios developer says the long-rumored Halo MMO, code-named “Titan,” was scrapped to serve a short-term executive payout. In a series of posts on X, Carl Sanford Joslyn Petersen (better known as “Sandy”), who worked at Ensemble, alleged that then-Xbox leader Don Mattrick shut down both the project and the studio because the game wouldn’t ship within his three-year bonus window.
“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,” Petersen said.
“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… 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,” he added.
Petersen added that Microsoft had internally modelled $1.1 billion in revenue for Titan and that the team had mapped out quest lines and home worlds, with players aligned to factions inspired by the Forerunners and Covenant (the Flood were planned but not playable).
Ensemble was shuttered in January 2009, with work on Titan believed to have taken place between 2004–2007 before the team pivoted to Halo Wars.
Petersen’s posts also included a blunt assessment of Mattrick’s tenure: “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?”
Microsoft has not commented on Petersen’s latest claims. During and after the studio’s closure, other Ensemble veterans previously attributed Titan’s cancellation to internal reorganization and cost/risk concerns around building an MMO.

It’s always interesting to hear behind-the-scenes stories about game development. The decision to scrap a project like Halo MMO must have been tough, but it’s fascinating to learn about the factors that influence such choices. Thanks for sharing this insight!
I completely agree! It’s fascinating how business decisions can impact creative projects. The Halo franchise has such a rich lore, so it’s a shame we didn’t get to see that MMO come to life. It makes you wonder what other hidden gems might have been shelved for similar reasons.
Absolutely! It’s interesting to think about how the pressure for financial success can overshadow innovative ideas in the gaming industry. The potential of a Halo MMO could have opened up new storytelling avenues and player experiences, which makes its cancellation even more poignant.
creative ambitions in game development. It’s a tough balance, especially when franchises like Halo have such high expectations. The decision to scrap “Titan” really highlights the challenges studios face in innovating while also meeting financial goals.
Absolutely, balancing creative ambitions with business decisions can be really challenging. The Halo franchise has such a rich lore that an MMO could have explored so many unique storytelling avenues. It’s interesting to think about how different the gaming landscape might look if “Titan” had been developed.