This comes from an over hour-long extensive preview video showing in-game footage of four-player co-op in the classic split screen format, despite only online co-op having a specified release window. The exact date of the Insider flight test, which will allow certain Halo Insider users to try out the co-op campaign prior to its full launch, is still undetermined.
However, 343 Industries community director, Brian Jarrard, stated in a Twitter post “Still hoping for this week (the week starting July 11)”, and “it’s day by day as work continues”. The update will also include a mission replay feature, which, much like co-op, has been a staple of the franchise since its inception. However, Halo Infinite’s pivot to an open-world presumably made its implementation more complicated than in past titles.
The co-op campaign was initially slated to release in May alongside the launch of Halo Infinite’s second season, but the full update got pushed back to late August, with it only supporting online co-op to start with.
Recently, Halo veteran Paul Bertone joined 343 Industries as the studio technical design director. Bertone’s extensive experience with the franchise includes working on the original trilogy, 3: ODST, and Reach.
NME awarded the Halo Infinite campaign five out of five stars: “Halo Infinite feels as immediately compelling and necessary as Bungie’s original games, and is a shining beacon in a year that has felt quite underwhelming in the AAA space. Intense combat and a keen sense of creativity make this a must-play, even if you’re not typically a fan of the genre or even Mr Mean and Green himself.”