id Software's John Carmack began his annual QuakeCon keynote apologizing to PC gamers for the state of the studio's latest shooter, Rage.

During his speech, Carmack acknowledged that the buggy game has generated ill feelings within the PC community, and that it had a lackluster ending. He also noted that the game's world itself was rather shell-like, offering very little in regards to virtual population. The lack of driver support was also "problematic," calling it "really, really poorly handled" and a lesson the studio learned for future titles.

But he also acknowledged that most of the studio's resources were shifted over to Doom 4 once the post-apocalyptic game hit the streets. Because of that, there has been relatively little time to fix the PC version's problems since its launch although several patches have improved its performance.

Carmack also admitted that he was disappointed with the marketing aspect for Rage, saying that it led customers to believe the mutant-filled FPS was more like similarly-themed RPGs on the market. "People expected it to be more like Fallout or Borderlands but that was never our intention,” Carmack said. "That hurt us in that the single-player was long for a shooter but very short for people expecting an RPG. The messaging on Rage wasn’t all it should have been."

Rage wasn't the only project giving way to Doom 4. Carmack said that id Software's mobile branch has been shut down as the studio focuses on getting the next Doom sequel out the door.

"We did make the decision to close up our mobile development, which saddens me a lot, in that I love doing the mobile work -- taking that time, spending a month, a year or something working on a mobile project," Carmack explained (transcribed by The Verge). "But we had some developers on there that we wanted to bring onto the Doom 4 project."

"It was looked at as something that, yes, this is fun. This is fun for the company, and it's entertaining and it makes money. But it's not a grand slam sort of thing on there," he added. "The Bethesda family really is about swinging for the fences. I hope we get back to mobile in various ways in the future, but the big real aim is blockbuster, AAA titles, and for id, that means Doom 4. It means that we get the whole company behind that after we get Doom 3: BFG Edition out the door. Essentially everybody will be focused on Doom 4 as a project."

Carmack went on to admit that the studio had actually finished an iOS project which is now on indefinite hold. "Unfortunately, we have a couple projects. We have an iPhone project that's sitting in the can right now with the rest of the Doom classics stuff, but we just havent been able to push it through," Carmack explained. "We're going to hold off until some appropriate time -- maybe we can do it with the Doom 3: BFG stuff on there."

As for when Doom 4 would be complete, Carmack wouldn't specify. "Every decade there will be a Doom," Carmack said, "but hopefully we can do better than that." In other words, it'll be done when it's done.