"Payday in Space".
This little nugget was found from the Swedish write-up of their financial report which is publicly available. Courtesy of Google Translation sorcery, Swedish is decipherable.
The report was sniffed out by the enemy of many a PR and marketing department:. Below is the Swedish to English report on Starbreeze's Storm.
"Starbreeze runs a game project with the working title storm. The game is based on a proprietary concept and is based on the technology behind Payday games. Storm can almost be summed up as "Payday in space." it is a co-op shooter in a sci-fi environment that takes advantage of the design we have created in Payday games.”
Heists in space? It's not exactly clear on the gameplay itself, only that they make use of the technology and methods from Payday, and that it's a co-op shooter. You can check out the financial report.