Halo Infinite’s campaign co-op test will support up to four players across PC, Xbox and Xbox Cloud Gaming. As Katharine explained when the test window was announced at the start of this month, joining co-op is just like starting a Fireteam in multiplayer. Once you’ve done that, you should be able to select Start Co-op from the main menu and take on Zeta Halo with your pals. Thankfully, 343 have worked things out so every player will keep their progress as they work their way through a co-op campaign, along with any upgrades and Spartan Cores collected. 343 say that the chance to replay missions is also coming along with campaign co-op. While replaying was relatively straightforward in older, more linear Halo games, Infinite’s open-world nature made things a little trickier to accomplish. The way 343 have got round this is by using the game’s tactical map, or tac-map. Select a completed mission from the tac-map in either solo or co-op, and you’ll be prompted to choose your difficulty and whether to activate any Skulls you or your friends have picked up. Replaying a mission resets it and teleports you to its starting location. Hey Presto, Big John Halo’s your uncle. Brendan was glad to have an open-world to explore in his Halo Infinite review. “It has taken the series a while to look outside its corridor shooting monoculture for inspiration,” he said. “But now that developers 343 Industries have broadened that corridor to the width of plains and stretched it to the height of mountains, it’ll be hard to go back.” The campaign co-op beta for Halo Infinite is due to land sometime this week and lasts until July 22nd. The full co-op and mission replay launch is expected in August. There’s more info about what’s coming on the Halo Waypoint site here. Are you happy at the idea of finally teaming up with other Spartans?