Halo 4, the first numbered entry in the series developed outside of Bungie Studios, won praise across the board and generated $220 million in day-one revenue. Despite this success, developer 343 Industries said that it suffered a handful of setbacks with the game, promising future entries will be better.

"We have a lot to learn. We made a lot of mistakes. We can do better," Halo franchise director Frank O'Connor said in a retrospective blog post. "And we know this, and we will."

O'Connor said there were a "ton" of things 343 wished it had done better with Halo 4, including the implementation of features that didn't make it into the final game, various glitches that surfaced, "DLC fiascos," and communication breakdowns.

The developer didn't only focus on the negatives in the blog post, admitting that "for a first effort, [Halo 4] wasn't half bad." Bright spots during the development of Halo 4 included the formation of a tight-knit development team and the overhaul of the game engine, he said.

O'Connor further explained that stepping into Bungie's "oversized" shoes would have been a challenge for any developer, noting the venture "terrified" the team at the onset. However, as the studio grew and 343 Industries began to feel comfortable, those fears were quelled, especially once Halo 4 finally hit shelves in November.

"We altered the engine. We expanded the universe. We innovated in storytelling, technology, and even marketing. It wasn’t flawless by any stretch of the imagination, but by most objective criteria, it was a resounding success," O'Connor said. "So we know we have a lot to do. And we know we have a lot to learn. But we also know that we now have the capacity, the teamwork, the technology and the experience to do much better next time."

O'Connor didn't lay out any specific plans for the future of the Halo brand, though he specifically stated that 343 Industries is capable of doing something "genuinely amazing" on next-generation hardware. Microsoft has previously confirmed Halo 5 and Halo 6 by way of announcing the Reclaimer Trilogy. Additionally, Microsoft has been openly hiring for a next-generation Halo title since July 2012.

A next-generation Xbox is rumored to hit store shelves this fall.