For the first official developer status update to the hack'n'slash Krater: Shadows Over Solstide, the folks at Fatshark let us know that the co-operative mode for the title is finally in its testing stage, and will soon be available, and also show some concept art for some co-op focused content that's in the pipelines:
But we do know that it is closing in. The first step – the Online game mode has been published for external testing as I am writing this and we are aiming to add it to the Steam build during the coming weeks.
So how do one get hold of a coop beta key? More details about their whereabouts will soon be revealed. But a safe bet is to look for them in the Underworld of Solside while playing the single player campaign in online mode.