The Games in Development section on the Starbreeze Website has a recently added listing for an unannounced co-op, science fiction FPS game called Storm. There is nothing there yet but an image and the following three lines: "Currently in development. Co-op Sci Fi FPS. It is our future." VG247 notes that that section does not have a listing for Cold Mercury, a "freemium" game announced early last year, so it's possible this is a new title for that project.