It's been almost five years since the last main-series Halo game, Halo 5: Guardians, but developer 343 Industries has a few good reasons why Halo Infinite development has taken so long. In the absence of new releases, the series has still seen some success with the release of Halo: The Master Chief Collection on PC, which made Halo Steam's top-selling game for a time in December.
Originally revealed at E3 2018, Halo Infinite appears to be attempting to return to the franchise's roots. Halo Infinite's first trailer revealed it would return to the Covenant's massive Halo Array rings, which give the series its name. Few things are already known about Halo Infinite, other than the fact that it will be a direct follow-up to Halo 5 in terms of story. It's also been teased that Halo Infinite could be a live-service game. While unconfirmed as of yet, this would allow for a potentially infinite influx of new content, which could be the origin of the game's name.
What's also seemed infinite is the long wait for Halo's next big game. Speaking to IGN in early 2019, Bonnie Ross, founder and head of 343 Industries, said part of the long delay between titles was caused by technical issues. Halo 4 and 5's game engine was overly technical, making it hard for developers to do creative work, so 343 Industries had to create the new Slipspace Engine to support "the future of Halo." In addition to providing a new technical foundation for the series, Ross also said Halo Infinite is a "spiritual" reboot of sorts, which likely meant the team needed to commit extra time to getting the game's story right.
343 Industries' Kiki Wolfkill, the developer's head of transmedia and entertainment, later elaborated on this in an interview with GamesIndustry.biz. According to Wolfkill, the goal is begin the next generation of Halo games by making a story anyone can jump into, even if they've never played a Halo game before. This means that, while it will still be a direct sequel to Halo 5, Halo Infinite is meant to rediscover what a Halo game is, 19 years after the original game launched.
Unfortunately, it's possible that fans will have to wait even longer than expected for Halo Infinite. Just a few months after the game's holiday 2020 release date was announced, Halo Infinite lost its creative director. Soon after that, Halo Infinite's lead producer left. A Halo community manager then told fans there was "no creative dilemma" in the studio and "no writing on the walls," but it's difficult to believe such important leadership's departure so close to Halo Infinite's intended release window isn't cause for concern. In a year as full of big game delays as 2020 is so far, it wouldn't be surprising for Microsoft to announce a Halo Infinite delay.
Halo Infinite is set to release in holiday 2020 alongside the Xbox Series X.