One-time Microsoft Games Studios boss Ed Fries has said that the Xbox's reliance on the Halo series was "almost a curse" for the franchise.

Speaking to OXM, Fries was asked where the Xbox would be without the Halo franchise. "I don't know. That's a really hard question. Did the machine make Halo or did Halo make the machine?"

"In the later years it was almost a curse from my point of view, because it had becomes so important to Xbox that it started to affect Halo."

"When people think that the most important part of the Xbox is Halo, then Halo has to be there for the launch of Xbox 360 or it can't miss its date [even though] that's gonna make a worse Halo... It's like Halo becomes more important than the Xbox, and I never wanted it to be that way."

Fries also said an over-reliance on Halo was against his interests, and that Microsoft needed to foster new hits alongside maintaining existing successes. "For me it was always about trying to make sure every game could be the best it could be and that the platform was a place where we could have lots of successful games like Halo, not just Halo."

"If it's all about Halo then you spend all your time working on Halo, you never discover Gears of War or anything else."

Fries also revealed that nobody at Microsoft expected the staggering success of the original Halo: Combat Evolved with the launch of the original Xbox in 2001, and that he initially predicted that Oddworld: Munch's Odyssey would become the hardware's launch hit. "You know, honestly we didn't know. I think anyone who tells you that they knew that was going to happen isn't telling the truth."

"There was a small set of games we had decided to spend all of our TV money. And Halo was one of those, so that's proof it was one of the games that we decided to make a bet on, but honestly if you'd asked me ahead of time I'd have said we're going to sell more from Lorne Lanning, an established console developer with a continuation of an existing console franchise that had previously been successful."

Current Microsoft Games Studios boss Phil Spencer said earlier this year that Microsoft "lost its way" with the Halo franchise and that developer 343 Industries could take over the series "without missing a beat".

Halo: Combat Evolved Anniversary, an updated version of the original game, will be released for Xbox 360 on November 15.