Though the single player component for the underwater horror adventure Debris came out in October 2017, the game still wasn't complete yet. That will all change when the team at Moonray Studios releases the game's new co-op mode on February 26.
Escape Together or Die AloneDive into:

During the co-op release window, the game will have a special 50% discount. Debris is available for Windows and OS X. You can find it via Steam or the Humble Store.