Marvel's Guardians of the Galaxy was set to have a multiplayer mode at one stage, according to information dug up from LinkedIn via Resetera's forums.
The LinkedIn account, for someone named Simon Laroche, suggests that the feature was cancelled early in development. He lists "online gameplay director" as one of his previous jobs on Guardians of the Galaxy, which strongly suggests that the game had a multiplayer element early on in development. The game has been confirmed by Square Enix to only feature a single-player mode.
It's a shame that multiplayer won't be making it to the game, honestly, but Marvel's Avengers is already filling that gap, with a rather lacklustre single-player, so it's refreshing to see Guardians of the Galaxy flip the priority there. The exact reason why multiplayer was cancelled though is not entirely clear.
Marvel's Guardians of the Galaxy is set for release on the 26th of October on PC, Xbox and PlayStation consoles as well as a cloud release on Nintendo Switch.